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18 results on '"Vydrov, Oleg"'

1. Nonlocal van der Waals density functional: The simpler the better

Author

Vydrov, Oleg A. and Van Voorhis, Troy

Subjects
Physics - Chemical Physics
Abstract

We devise a nonlocal correlation energy functional that describes the entire range of dispersion interactions in a seamless fashion using only the electron density as input. The new functional is considerably simpler than its predecessors of a similar type. The functional has a tractable and robust analytic form that lends itself to efficient self-consistent implementation. When paired with an appropriate exchange functional, our nonlocal correlation model yields accurate interaction energies of weakly-bound complexes, not only near the energy minima but also far from equilibrium. Our model exhibits an outstanding precision at predicting equilibrium intermonomer separations in van der Waals complexes. It also gives accurate covalent bond lengths and atomization energies. Hence the functional proposed in this work is a computationally inexpensive electronic structure tool of broad applicability.

Published
2010
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2. Dispersion interactions from a local polarizability model

Author

Vydrov, Oleg A. and Van Voorhis, Troy

Subjects
Physics - Chemical Physics
Abstract

A local approximation for dynamic polarizability leads to a nonlocal functional for the long-range dispersion interaction energy via an imaginary-frequency integral. We analyze several local polarizability approximations and argue that the form underlying the construction of our recent van der Waals functional [O. A. Vydrov and T. Van Voorhis, Phys. Rev. Lett. 103, 063004 (2009)] is particularly well physically justified. Using this improved formula, we compute dynamic dipole polarizabilities and van der Waals C_6 coefficients for a set of atoms and molecules. Good agreement with the benchmark values is obtained in most cases.

Published
2010
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3. Assessing the Performance of Recent Density Functionals for Bulk Solids

Author

Csonka, Gabor I., Perdew, John P., Ruzsinszky, Adrienn, Philipsen, Pier H. T., Lebegue, Sebastien, Paier, Joachim, Vydrov, Oleg A., and Angyan, Janos G.

Subjects
Condensed Matter - Materials Science
Abstract

We assess the performance of recent density functionals for the exchange-correlation energy of a nonmolecular solid, by applying accurate calculations with the GAUSSIAN, BAND, and VASP codes to a test set of 24 solid metals and non-metals. The functionals tested are the modified Perdew-Burke-Ernzerhof generalized gradient approximation (PBEsol GGA), the second-order GGA (SOGGA), and the Armiento-Mattsson 2005 (AM05) GGA. For completeness, we also test more-standard functionals: the local density approximation, the original PBE GGA, and the Tao-Perdew-Staroverov-Scuseria (TPSS) meta-GGA. We find that the recent density functionals for solids reach a high accuracy for bulk properties (lattice constant and bulk modulus). For the cohesive energy, PBE is better than PBEsol overall, as expected, but PBEsol is actually better for the alkali metals and alkali halides. For fair comparison of calculated and experimental results, we consider the zero-point phonon and finite-temperature effects ignored by many workers. We show how Gaussian basis sets and inaccurate experimental reference data may affect the rating of the quality of the functionals. The results show that PBEsol and AM05 perform somewhat differently from each other for alkali metal, alkaline earth metal and alkali halide crystals (where the maximum value of the reduced density gradient is about 2), but perform very similarly for most of the other solids (where it is often about 1). Our explanation for this is consistent with the importance of exchange-correlation nonlocality in regions of core-valence overlap., Comment: 32 pages, single pdf file

Published
2009
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4. Restoring the density-gradient expansion for exchange in solids and surfaces

Author

Perdew, John P., Ruzsinszky, Adrienn, Csonka, Gabor I., Vydrov, Oleg A., Scuseria, Gustavo E., Constantin, Lucian A., Zhou, Xiaolan, and Burke, Kieron

Subjects
Condensed Matter - Materials Science
Abstract

Successful modern generalized gradient approximations (GGA's) are biased toward atomic energies. Restoration of the first-principles gradient expansion for exchange over a wide range of density gradients eliminates this bias. We introduce PBEsol, a revised Perdew-Burke-Ernzerhof GGA that improves equilibrium properties of densely-packed solids and their surfaces., Comment: 4 pages, 2 figures

Published
2007
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5. Generalized gradient approximation for solids and their surfaces

Author

Perdew, John P., Ruzsinszky, Adrienn, Csonka, Gabor I., Vydrov, Oleg A., Scuseria, Gustavo E., Constantin, Lucian A., Zhou, Xiaolan, and Burke, Kieron

Subjects
Condensed Matter - Other Condensed Matter, Condensed Matter - Materials Science
Abstract

Successful modern generalized gradient approximations (GGA) are biased toward atomic energies. Restoration of the first-principles gradient expansion for the exchange energy over a wide range of density gradients eliminates this bias. We introduce PBEsol, a revised Perdew-Burke-Ernzerhof GGA that improves equilibrium properties for many densely-packed solids and their surfaces., Comment: 4pages, 2figures,2tables

Published
2007
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6. Exchange and Correlation in Open Systems of Fluctuating Electron Number

Author

Perdew, John P., Ruzsinszky, Adrienn, Csonka, Gábor I., Vydrov, Oleg A., Scuseria, Gustavo E., Staroverov, Viktor N., and Tao, Jianmin

Subjects
Condensed Matter - Materials Science
Abstract

While the exact total energy of a separated open system varies linearly as a function of average electron number between adjacent integers, the energy predicted by semi-local density functional approximations curves upward and the exact-exchange-only or Hartree-Fock energy downward. As a result, semi-local density functionals fail for separated open systems of fluctuating electron number, as in stretched molecular ions A$_2^{+}$ and in solid transition metal oxides. We develop an exact-exchange theory and an exchange-hole sum rule that explain these failures and we propose a way to correct them via a local hybrid functional., Comment: 4 pages, 2 figures

Published
2007
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7. Software for the frontiers of quantum chemistry: An overview of developments in the Q-Chem 5 package

Author

Epifanovsky, Evgeny, Gilbert, Andrew T. B., Feng, Xintian, Lee, Joonho, Mao, Yuezhi, Mardirossian, Narbe, Pokhilko, Pavel, White, Alec F., Coons, Marc P., Dempwolff, Adrian L., Gan, Zhengting, Hait, Diptarka, Horn, Paul R., Jacobson, Leif D., Kaliman, Ilya, Kussmann, Jörg, Lange, Adrian W., Lao, Ka Un, Levine, Daniel S., Liu, Jie, McKenzie, Simon C., Morrison, Adrian F., Nanda, Kaushik D., Plasser, Felix, Rehn, Dirk R., Vidal, Marta L., You, Zhi-Qiang, Zhu, Ying, Alam, Bushra, Albrecht, Benjamin J., Aldossary, Abdulrahman, Alguire, Ethan, Andersen, Josefine H., Athavale, Vishikh, Barton, Dennis, Begam, Khadiza, Behn, Andrew, Bellonzi, Nicole, Bernard, Yves A., Berquist, Eric J., Burton, Hugh G. A., Carreras, Abel, Carter-Fenk, Kevin, Chakraborty, Romit, Chien, Alan D., Closser, Kristina D., Cofer-Shabica, Vale, Dasgupta, Saswata, de Wergifosse, Marc, Deng, Jia, Diedenhofen, Michael, Do, Hainam, Ehlert, Sebastian, Fang, Po-Tung, Fatehi, Shervin, Feng, Qingguo, Friedhoff, Triet, Gayvert, James, Ge, Qinghui, Gidofalvi, Gergely, Goldey, Matthew, Gomes, Joe, González-Espinoza, Cristina E., Gulania, Sahil, Gunina, Anastasia O., Hanson-Heine, Magnus W. D., Harbach, Phillip H. P., Hauser, Andreas, Herbst, Michael F., Hernández Vera, Mario, Hodecker, Manuel, Holden, Zachary C., Houck, Shannon, Huang, Xunkun, Hui, Kerwin, Huynh, Bang C., Ivanov, Maxim, Jász, Ádám, Ji, Hyunjun, Jiang, Hanjie, Kaduk, Benjamin, Kähler, Sven, Khistyaev, Kirill, Kim, Jaehoon, Kis, Gergely, Klunzinger, Phil, Koczor-Benda, Zsuzsanna, Koh, Joong Hoon, Kosenkov, Dimitri, Koulias, Laura, Kowalczyk, Tim, Krauter, Caroline M., Kue, Karl, Kunitsa, Alexander, Kus, Thomas, Ladjánszki, István, Landau, Arie, Lawler, Keith V., Lefrancois, Daniel, Lehtola, Susi, Li, Run R., Li, Yi-Pei, Liang, Jiashu, Liebenthal, Marcus, Lin, Hung-Hsuan, Lin, You-Sheng, Liu, Fenglai, Liu, Kuan-Yu, Loipersberger, Matthias, Luenser, Arne, Manjanath, Aaditya, Manohar, Prashant, Mansoor, Erum, Manzer, Sam F., Mao, Shan-Ping, Marenich, Aleksandr V., Markovich, Thomas, Mason, Stephen, Maurer, Simon A., McLaughlin, Peter F., Menger, Maximilian F. S. J., Mewes, Jan-Michael, Mewes, Stefanie A., Morgante, Pierpaolo, Mullinax, J. Wayne, Oosterbaan, Katherine J., Paran, Garrette, Paul, Alexander C., Paul, Suranjan K., Pavošević, Fabijan, Pei, Zheng, Prager, Stefan, Proynov, Emil I., Rák, Ádám, Ramos-Cordoba, Eloy, Rana, Bhaskar, Rask, Alan E., Rettig, Adam, Richard, Ryan M., Rob, Fazle, Rossomme, Elliot, Scheele, Tarek, Scheurer, Maximilian, Schneider, Matthias, Sergueev, Nickolai, Sharada, Shaama M., Skomorowski, Wojciech, Small, David W., Stein, Christopher J., Su, Yu-Chuan, Sundstrom, Eric J., Tao, Zhen, Thirman, Jonathan, Tornai, Gábor J., Tsuchimochi, Takashi, Tubman, Norm M., Veccham, Srimukh Prasad, Vydrov, Oleg, Wenzel, Jan, Witte, Jon, Yamada, Atsushi, Yao, Kun, Yeganeh, Sina, Yost, Shane R., Zech, Alexander, Zhang, Igor Ying, Zhang, Xing, Zhang, Yu, Zuev, Dmitry, Aspuru-Guzik, Alán, Bell, Alexis T., Besley, Nicholas A., Bravaya, Ksenia B., Brooks, Bernard R., Casanova, David, Chai, Jeng-Da, Coriani, Sonia, Cramer, Christopher J., Cserey, György, DePrince, A. Eugene, DiStasio, Robert A., Dreuw, Andreas, Dunietz, Barry D., Furlani, Thomas R., Goddard, William A., Hammes-Schiffer, Sharon, Head-Gordon, Teresa, Hehre, Warren J., Hsu, Chao-Ping, Jagau, Thomas-C, Jung, Yousung, Klamt, Andreas, Kong, Jing, Lambrecht, Daniel S., Liang, WanZhen, Mayhall, Nicholas J., McCurdy, C. William, Neaton, Jeffrey B., Ochsenfeld, Christian, Parkhill, John A., Peverati, Roberto, Rassolov, Vitaly A., Shao, Yihan, Slipchenko, Lyudmila V., Stauch, Tim, Steele, Ryan P., Subotnik, Joseph E., Thom, Alex J. W., Tkatchenko, Alexandre, Truhlar, Donald G., Van Voorhis, Troy, Wesolowski, Tomasz A., Whaley, K. Birgitta, Woodcock, H. Lee, Zimmerman, Paul M., Faraji, Shirin, Gill, Peter M. W., Head-Gordon, Martin, Herbert, John M., Krylov, Anna I., Epifanovsky, Evgeny, Gilbert, Andrew T. B., Feng, Xintian, Lee, Joonho, Mao, Yuezhi, Mardirossian, Narbe, Pokhilko, Pavel, White, Alec F., Coons, Marc P., Dempwolff, Adrian L., Gan, Zhengting, Hait, Diptarka, Horn, Paul R., Jacobson, Leif D., Kaliman, Ilya, Kussmann, Jörg, Lange, Adrian W., Lao, Ka Un, Levine, Daniel S., Liu, Jie, McKenzie, Simon C., Morrison, Adrian F., Nanda, Kaushik D., Plasser, Felix, Rehn, Dirk R., Vidal, Marta L., You, Zhi-Qiang, Zhu, Ying, Alam, Bushra, Albrecht, Benjamin J., Aldossary, Abdulrahman, Alguire, Ethan, Andersen, Josefine H., Athavale, Vishikh, Barton, Dennis, Begam, Khadiza, Behn, Andrew, Bellonzi, Nicole, Bernard, Yves A., Berquist, Eric J., Burton, Hugh G. A., Carreras, Abel, Carter-Fenk, Kevin, Chakraborty, Romit, Chien, Alan D., Closser, Kristina D., Cofer-Shabica, Vale, Dasgupta, Saswata, de Wergifosse, Marc, Deng, Jia, Diedenhofen, Michael, Do, Hainam, Ehlert, Sebastian, Fang, Po-Tung, Fatehi, Shervin, Feng, Qingguo, Friedhoff, Triet, Gayvert, James, Ge, Qinghui, Gidofalvi, Gergely, Goldey, Matthew, Gomes, Joe, González-Espinoza, Cristina E., Gulania, Sahil, Gunina, Anastasia O., Hanson-Heine, Magnus W. D., Harbach, Phillip H. P., Hauser, Andreas, Herbst, Michael F., Hernández Vera, Mario, Hodecker, Manuel, Holden, Zachary C., Houck, Shannon, Huang, Xunkun, Hui, Kerwin, Huynh, Bang C., Ivanov, Maxim, Jász, Ádám, Ji, Hyunjun, Jiang, Hanjie, Kaduk, Benjamin, Kähler, Sven, Khistyaev, Kirill, Kim, Jaehoon, Kis, Gergely, Klunzinger, Phil, Koczor-Benda, Zsuzsanna, Koh, Joong Hoon, Kosenkov, Dimitri, Koulias, Laura, Kowalczyk, Tim, Krauter, Caroline M., Kue, Karl, Kunitsa, Alexander, Kus, Thomas, Ladjánszki, István, Landau, Arie, Lawler, Keith V., Lefrancois, Daniel, Lehtola, Susi, Li, Run R., Li, Yi-Pei, Liang, Jiashu, Liebenthal, Marcus, Lin, Hung-Hsuan, Lin, You-Sheng, Liu, Fenglai, Liu, Kuan-Yu, Loipersberger, Matthias, Luenser, Arne, Manjanath, Aaditya, Manohar, Prashant, Mansoor, Erum, Manzer, Sam F., Mao, Shan-Ping, Marenich, Aleksandr V., Markovich, Thomas, Mason, Stephen, Maurer, Simon A., McLaughlin, Peter F., Menger, Maximilian F. S. J., Mewes, Jan-Michael, Mewes, Stefanie A., Morgante, Pierpaolo, Mullinax, J. Wayne, Oosterbaan, Katherine J., Paran, Garrette, Paul, Alexander C., Paul, Suranjan K., Pavošević, Fabijan, Pei, Zheng, Prager, Stefan, Proynov, Emil I., Rák, Ádám, Ramos-Cordoba, Eloy, Rana, Bhaskar, Rask, Alan E., Rettig, Adam, Richard, Ryan M., Rob, Fazle, Rossomme, Elliot, Scheele, Tarek, Scheurer, Maximilian, Schneider, Matthias, Sergueev, Nickolai, Sharada, Shaama M., Skomorowski, Wojciech, Small, David W., Stein, Christopher J., Su, Yu-Chuan, Sundstrom, Eric J., Tao, Zhen, Thirman, Jonathan, Tornai, Gábor J., Tsuchimochi, Takashi, Tubman, Norm M., Veccham, Srimukh Prasad, Vydrov, Oleg, Wenzel, Jan, Witte, Jon, Yamada, Atsushi, Yao, Kun, Yeganeh, Sina, Yost, Shane R., Zech, Alexander, Zhang, Igor Ying, Zhang, Xing, Zhang, Yu, Zuev, Dmitry, Aspuru-Guzik, Alán, Bell, Alexis T., Besley, Nicholas A., Bravaya, Ksenia B., Brooks, Bernard R., Casanova, David, Chai, Jeng-Da, Coriani, Sonia, Cramer, Christopher J., Cserey, György, DePrince, A. Eugene, DiStasio, Robert A., Dreuw, Andreas, Dunietz, Barry D., Furlani, Thomas R., Goddard, William A., Hammes-Schiffer, Sharon, Head-Gordon, Teresa, Hehre, Warren J., Hsu, Chao-Ping, Jagau, Thomas-C, Jung, Yousung, Klamt, Andreas, Kong, Jing, Lambrecht, Daniel S., Liang, WanZhen, Mayhall, Nicholas J., McCurdy, C. William, Neaton, Jeffrey B., Ochsenfeld, Christian, Parkhill, John A., Peverati, Roberto, Rassolov, Vitaly A., Shao, Yihan, Slipchenko, Lyudmila V., Stauch, Tim, Steele, Ryan P., Subotnik, Joseph E., Thom, Alex J. W., Tkatchenko, Alexandre, Truhlar, Donald G., Van Voorhis, Troy, Wesolowski, Tomasz A., Whaley, K. Birgitta, Woodcock, H. Lee, Zimmerman, Paul M., Faraji, Shirin, Gill, Peter M. W., Head-Gordon, Martin, Herbert, John M., and Krylov, Anna I.

Abstract

This article summarizes technical advances contained in the fifth major release of the Q-Chem quantum chemistry program package, covering developments since 2015. A comprehensive library of exchange–correlation functionals, along with a suite of correlated many-body methods, continues to be a hallmark of the Q-Chem software. The many-body methods include novel variants of both coupled-cluster and configuration-interaction approaches along with methods based on the algebraic diagrammatic construction and variational reduced density-matrix methods. Methods highlighted in Q-Chem 5 include a suite of tools for modeling core-level spectroscopy, methods for describing metastable resonances, methods for computing vibronic spectra, the nuclear–electronic orbital method, and several different energy decomposition analysis techniques. High-performance capabilities including multithreaded parallelism and support for calculations on graphics processing units are described. Q-Chem boasts a community of well over 100 active academic developers, and the continuing evolution of the software is supported by an “open teamware” model and an increasingly modular design.

Published
2021

8. Advances in molecular quantum chemistry contained in the Q-Chem 4 program package

Author

Shao, Yihan, Gan, Zhengting, Epifanovsky, Evgeny, Gilbert, Andrew T. B., Wormit, Michael, Kussmann, Joerg, Lange, Adrian W., Behn, Andrew, Deng, Jia, Feng, Xintian, Ghosh, Debashree, Stein, Tamar, Stück, David, Su, Yu-Chuan, Thom, Alex J.W., Tsuchimochi, Takashi, Vanovschi, Vitalii, Vogt, Leslie, Vydrov, Oleg, Wang, Tao, Watson, Mark A., Goldey, Matthew, Wenzel, Jan, White, Alec, Williams, Christopher F., Yang, Jun, Yeganeh, Sina, Yost, Shane R., You, Zhi-Qiang, Zhang, Igor Ying, Zhang, Xing, Zhao, Yan, Horn, Paul R., Brooks, Bernard R., Chan, Garnet K.L., Chipman, Daniel M., Cramer, Christopher J., Goddard, William A., Gordon, Mark S., Hehre, Warren, Klamt, Andreas, Schaefer, Henry F., Schmidt, Michael W., Jacobson, Leif D., Sherrill, C. David, Truhlar, Donald G., Warshel, Arieh, Xu, Xin, Aspuru-Guzik, Alán, Baer, Roi, Bell, Alexis T., Besley, Nicholas A., Chai, Jeng-Da, Dreuw, Andreas, Kaliman, Ilya, Dunietz, Barry D., Furlani, Thomas R., Gwaltney, Steven R., Hsu, Chao-Ping, Jung, Yousung, Kong, Jing, Lambrecht, Daniel S., Liang, WanZhen, Ochsenfeld, Christian, Rassolov, Vitaly A., Khaliullin, Rustam Z., Slipchenko, Lyudmila V., Subotnik, Joseph E., Van Voorhis, Troy, Herbert, John M., Krylov, Anna I., Gill, Peter M.W., Head-Gordon, Martin, Kuś, Tomasz, Landau, Arie, Liu, Jie, Proynov, Emil I., Rhee, Young Min, Richard, Ryan M., Rohrdanz, Mary A., Steele, Ryan P., Sundstrom, Eric J., Woodcock, H. Lee, Zimmerman, Paul M., Zuev, Dmitry, Albrecht, Ben, Alguire, Ethan, Austin, Brian, Beran, Gregory J. O., Bernard, Yves A., Berquist, Eric, Brandhorst, Kai, Bravaya, Ksenia B., Brown, Shawn T., Casanova, David, Chang, Chun-Min, Chen, Yunqing, Chien, Siu Hung, Closser, Kristina D., Crittenden, Deborah L., Diedenhofen, Michael, DiStasio, Robert A., Do, Hainam, Dutoi, Anthony D., Edgar, Richard G., Fatehi, Shervin, Fusti-Molnar, Laszlo, Ghysels, An, Golubeva-Zadorozhnaya, Anna, Gomes, Joseph, Hanson-Heine, Magnus W.D., Harbach, Philipp H.P., Hauser, Andreas W., Hohenstein, Edward G., Holden, Zachary C., Jagau, Thomas-C., Ji, Hyunjun, Kaduk, Benjamin, Khistyaev, Kirill, Kim, Jaehoon, Kim, Jihan, King, Rollin A., Klunzinger, Phil, Kosenkov, Dmytro, Kowalczyk, Tim, Krauter, Caroline M., Lao, Ka Un, Laurent, Adèle D., Lawler, Keith V., Levchenko, Sergey V., Lin, Ching Yeh, Liu, Fenglai, Livshits, Ester, Lochan, Rohini C., Luenser, Arne, Manohar, Prashant, Manzer, Samuel F., Mao, Shan-Ping, Mardirossian, Narbe, Marenich, Aleksandr V., Maurer, Simon A., Mayhall, Nicholas J., Neuscamman, Eric, Oana, C. Melania, Olivares-Amaya, Roberto, O’Neill, Darragh P., Parkhill, John A., Perrine, Trilisa M., Peverati, Roberto, Prociuk, Alexander, Rehn, Dirk R., Rosta, Edina, Russ, Nicholas J., Sharada, Shaama M., Sharma, Sandeep, Small, David W., Sodt, Alexander, Shao, Yihan, Gan, Zhengting, Epifanovsky, Evgeny, Gilbert, Andrew T. B., Wormit, Michael, Kussmann, Joerg, Lange, Adrian W., Behn, Andrew, Deng, Jia, Feng, Xintian, Ghosh, Debashree, Stein, Tamar, Stück, David, Su, Yu-Chuan, Thom, Alex J.W., Tsuchimochi, Takashi, Vanovschi, Vitalii, Vogt, Leslie, Vydrov, Oleg, Wang, Tao, Watson, Mark A., Goldey, Matthew, Wenzel, Jan, White, Alec, Williams, Christopher F., Yang, Jun, Yeganeh, Sina, Yost, Shane R., You, Zhi-Qiang, Zhang, Igor Ying, Zhang, Xing, Zhao, Yan, Horn, Paul R., Brooks, Bernard R., Chan, Garnet K.L., Chipman, Daniel M., Cramer, Christopher J., Goddard, William A., Gordon, Mark S., Hehre, Warren, Klamt, Andreas, Schaefer, Henry F., Schmidt, Michael W., Jacobson, Leif D., Sherrill, C. David, Truhlar, Donald G., Warshel, Arieh, Xu, Xin, Aspuru-Guzik, Alán, Baer, Roi, Bell, Alexis T., Besley, Nicholas A., Chai, Jeng-Da, Dreuw, Andreas, Kaliman, Ilya, Dunietz, Barry D., Furlani, Thomas R., Gwaltney, Steven R., Hsu, Chao-Ping, Jung, Yousung, Kong, Jing, Lambrecht, Daniel S., Liang, WanZhen, Ochsenfeld, Christian, Rassolov, Vitaly A., Khaliullin, Rustam Z., Slipchenko, Lyudmila V., Subotnik, Joseph E., Van Voorhis, Troy, Herbert, John M., Krylov, Anna I., Gill, Peter M.W., Head-Gordon, Martin, Kuś, Tomasz, Landau, Arie, Liu, Jie, Proynov, Emil I., Rhee, Young Min, Richard, Ryan M., Rohrdanz, Mary A., Steele, Ryan P., Sundstrom, Eric J., Woodcock, H. Lee, Zimmerman, Paul M., Zuev, Dmitry, Albrecht, Ben, Alguire, Ethan, Austin, Brian, Beran, Gregory J. O., Bernard, Yves A., Berquist, Eric, Brandhorst, Kai, Bravaya, Ksenia B., Brown, Shawn T., Casanova, David, Chang, Chun-Min, Chen, Yunqing, Chien, Siu Hung, Closser, Kristina D., Crittenden, Deborah L., Diedenhofen, Michael, DiStasio, Robert A., Do, Hainam, Dutoi, Anthony D., Edgar, Richard G., Fatehi, Shervin, Fusti-Molnar, Laszlo, Ghysels, An, Golubeva-Zadorozhnaya, Anna, Gomes, Joseph, Hanson-Heine, Magnus W.D., Harbach, Philipp H.P., Hauser, Andreas W., Hohenstein, Edward G., Holden, Zachary C., Jagau, Thomas-C., Ji, Hyunjun, Kaduk, Benjamin, Khistyaev, Kirill, Kim, Jaehoon, Kim, Jihan, King, Rollin A., Klunzinger, Phil, Kosenkov, Dmytro, Kowalczyk, Tim, Krauter, Caroline M., Lao, Ka Un, Laurent, Adèle D., Lawler, Keith V., Levchenko, Sergey V., Lin, Ching Yeh, Liu, Fenglai, Livshits, Ester, Lochan, Rohini C., Luenser, Arne, Manohar, Prashant, Manzer, Samuel F., Mao, Shan-Ping, Mardirossian, Narbe, Marenich, Aleksandr V., Maurer, Simon A., Mayhall, Nicholas J., Neuscamman, Eric, Oana, C. Melania, Olivares-Amaya, Roberto, O’Neill, Darragh P., Parkhill, John A., Perrine, Trilisa M., Peverati, Roberto, Prociuk, Alexander, Rehn, Dirk R., Rosta, Edina, Russ, Nicholas J., Sharada, Shaama M., Sharma, Sandeep, Small, David W., and Sodt, Alexander

Abstract

A summary of the technical advances that are incorporated in the fourth major release of the Q-Chem quantum chemistry program is provided, covering approximately the last seven years. These include developments in density functional theory methods and algorithms, nuclear magnetic resonance (NMR) property evaluation, coupled cluster and perturbation theories, methods for electronically excited and open-shell species, tools for treating extended environments, algorithms for walking on potential surfaces, analysis tools, energy and electron transfer modelling, parallel computing capabilities, and graphical user interfaces. In addition, a selection of example case studies that illustrate these capabilities is given. These include extensive benchmarks of the comparative accuracy of modern density functionals for bonded and non-bonded interactions, tests of attenuated second order Møller–Plesset (MP2) methods for intermolecular interactions, a variety of parallel performance benchmarks, and tests of the accuracy of implicit solvation models. Some specific chemical examples include calculations on the strongly correlated Cr2 dimer, exploring zeolite-catalysed ethane dehydrogenation, energy decomposition analysis of a charged ter-molecular complex arising from glycerol photoionisation, and natural transition orbitals for a Frenkel exciton state in a nine-unit model of a self-assembling nanotube.

Published
2015

9. Nonlocal van der Waals density functional: The simpler the better

Author

Massachusetts Institute of Technology. Department of Chemistry, Van Voorhis, Troy, Vydrov, Oleg A., Massachusetts Institute of Technology. Department of Chemistry, Van Voorhis, Troy, and Vydrov, Oleg A.

Abstract

We devise a nonlocal correlation energy functional that describes the entire range of dispersion interactions in a seamless fashion using only the electron density as input. The new functional is considerably simpler than its predecessors of a similar type. The functional has a tractable and robust analytic form that lends itself to efficient self-consistent implementation. When paired with an appropriate exchange functional, our nonlocal correlation model yields accurate interaction energies of weakly-bound complexes, not only near the energy minima but also far from equilibrium. Our model exhibits an outstanding precision at predicting equilibrium intermonomer separations in van der Waals complexes. It also gives accurate covalent bond lengths and atomization energies. Hence the functional proposed in this work is a computationally inexpensive electronic structure tool of broad applicability., National Science Foundation (U.S.) (NSF CAREER Grant No. CHE-0547877), David & Lucile Packard Foundation (Fellowship)

Published
2012

10. Implementation and Assessment of a Simple Nonlocal van der Waals Density Functional

Author

Massachusetts Institute of Technology. Department of Chemistry, Van Voorhis, Troy, Vydrov, Oleg A., Massachusetts Institute of Technology. Department of Chemistry, Van Voorhis, Troy, and Vydrov, Oleg A.

Abstract

Recently we developed a nonlocal van der Waals density functional (VV09) that has a simple and well-behaved analytic form. In this article, we report a self-consistent implementation of VV09 with an atom-centered basis set. We compute binding energies for a diverse benchmark set and find that VV09 performs well in combination with Hartree–Fock exchange. We compare VV09 with its precursor, discuss likely sources of inaccuracies in both models, and identify some aspects of the methodology where further refinements are desirable., National Science Foundation (U.S.) (NSF CAREER Grant No. CHE-0547877), David & Lucile Packard Foundation (Fellowship)

Published
2012

11. Exchange and correlation in molecular wire conductance: non-locality is the key

Author

Massachusetts Institute of Technology. Department of Chemistry, Van Voorhis, Troy, Evans, Jeremy S., Vydrov, Oleg A., Massachusetts Institute of Technology. Department of Chemistry, Van Voorhis, Troy, Evans, Jeremy S., and Vydrov, Oleg A.

Abstract

We study real-time electron dynamics in a molecular junction with a variety of approximations to the electronic structure, toward the ultimate aim of determining what ingredients are crucial for the accurate prediction of charge transport. We begin with real-time, all electron simulations using some common density functionals that differ in how they treat long-range Hartree–Fock exchange. We find that the inclusion or exclusion of nonlocal exchange is the dominant factor determining the transport behavior, with all semilocal contributions having a smaller effect. In order to study nonlocal correlation, we first map our junction onto a simple Pariser–Parr–Pople (PPP) model Hamiltonian. The PPP dynamics are shown to faithfully reproduce the all electron results, and we demonstrate that nonlocal correlation can be readily included in the model space using the generator coordinate method (GCM). Our PPP-GCM simulations suggest that nonlocal correlation has a significant impact on the I-V character that is not captured even qualitatively by any of the common semilocal approximations to exchange and correlation. The implications of our results for transport calculations are discussed., National Science Foundation (U.S.) (CAREER under Grant No. CHE-0547877), David & Lucile Packard Foundation (Fellowship)

Published
2012

12. Dispersion interactions from a local polarizability model

Author

Massachusetts Institute of Technology. Department of Chemistry, Van Voorhis, Troy, Vydrov, Oleg A., Massachusetts Institute of Technology. Department of Chemistry, Van Voorhis, Troy, and Vydrov, Oleg A.

Abstract

A local approximation for dynamic polarizability leads to a nonlocal functional for the long-range dispersion interaction energy via an imaginary-frequency integral. We analyze several local polarizability approximations and argue that the form underlying the construction of our recent van der Waals functional [O. A. Vydrov and T. Van Voorhis, Phys. Rev. Lett. 103, 063004 (2009)] is particularly well physically justified. Using this improved formula, we compute dynamic dipole polarizabilities and van der Waals C6 coefficients for a set of atoms and molecules. Good agreement with the benchmark values is obtained in most cases., National Science Foundation (U.S.) (CAREER grant CHE-0547877)

Published
2011

13. Nonlocal van derWaals Density Functional Made Simple

Author

Massachusetts Institute of Technology. Department of Chemistry, Van Voorhis, Troy, Vydrov, Oleg A., Massachusetts Institute of Technology. Department of Chemistry, Van Voorhis, Troy, and Vydrov, Oleg A.

Abstract

We derive a nonlocal correlation functional that adequately describes van der Waals interactions not only in the asymptotic long-range regime but also at short range. Unlike its precursor, developed by Langreth, Lundqvist, and co-workers, the new functional has a simple analytic form, finite for all interelectron separations, well behaved in the slowly varying density limit, and generalized to spin-polarized systems., Packard Foundation, National Science Foundation

Published
2010

14. Vydrov and Van Voorhis reply

Author

Massachusetts Institute of Technology. Department of Chemistry, Van Voorhis, Troy, Vydrov, Oleg A., Massachusetts Institute of Technology. Department of Chemistry, Van Voorhis, Troy, and Vydrov, Oleg A.

Abstract

A Reply to the Comment by David C. Langreth and Bengt I. Lundqvist.

Published
2010

15. Assessing the performance of recent density functionals for bulk solids

Author

Massachusetts Institute of Technology. Department of Chemistry, Vydrov, Oleg A., Csonka, Gabor I., Perdew, John P., Ruzsinszky, Adrienn, Philipsen, Pier H., Lebegue, Sebastien, Paier, Joachim, Angyan, Janos G., Massachusetts Institute of Technology. Department of Chemistry, Vydrov, Oleg A., Csonka, Gabor I., Perdew, John P., Ruzsinszky, Adrienn, Philipsen, Pier H., Lebegue, Sebastien, Paier, Joachim, and Angyan, Janos G.

Abstract

We assess the performance of recent density functionals for the exchange-correlation energy of a nonmolecular solid, by applying accurate calculations with the GAUSSIAN, BAND, and VASP codes to a test set of 24 solid metals and nonmetals. The functionals tested are the modified Perdew-Burke-Ernzerhof generalized gradient approximation (PBEsol GGA), the second-order GGA (SOGGA), and the Armiento-Mattsson 2005 (AM05) GGA. For completeness, we also test more standard functionals: the local density approximation, the original PBE GGA, and the Tao-Perdew-Staroverov-Scuseria meta-GGA. We find that the recent density functionals for solids reach a high accuracy for bulk properties (lattice constant and bulk modulus). For the cohesive energy, PBE is better than PBEsol overall, as expected, but PBEsol is actually better for the alkali metals and alkali halides. For fair comparison of calculated and experimental results, we consider the zero-point phonon and finite-temperature effects ignored by many workers. We show how GAUSSIAN basis sets and inaccurate experimental reference data may affect the rating of the quality of the functionals. The results show that PBEsol and AM05 perform somewhat differently from each other for alkali metal, alkaline-earth metal, and alkali halide crystals (where the maximum value of the reduced density gradient is about 2), but perform very similarly for most of the other solids (where it is often about 1). Our explanation for this is consistent with the importance of exchange-correlation nonlocality in regions of core-valence overlap.

Published
2010

16. Nonlocal van der Waals density functional: the simpler the better

Author

Troy Van Voorhis, Oleg A. Vydrov, Massachusetts Institute of Technology. Department of Chemistry, Van Voorhis, Troy, and Vydrov, Oleg A.

Subjects
Physics, Chemical Physics (physics.chem-ph), Electron density, Work (thermodynamics), Range (particle radiation), 010304 chemical physics, General Physics and Astronomy, FOS: Physical sciences, 02 engineering and technology, Electronic structure, 021001 nanoscience & nanotechnology, 01 natural sciences, Maxima and minima, symbols.namesake, Physics - Chemical Physics, 0103 physical sciences, symbols, Statistical physics, Physical and Theoretical Chemistry, van der Waals force, 0210 nano-technology, Dispersion (chemistry), Energy functional
Abstract

We devise a nonlocal correlation energy functional that describes the entire range of dispersion interactions in a seamless fashion using only the electron density as input. The new functional is considerably simpler than its predecessors of a similar type. The functional has a tractable and robust analytic form that lends itself to efficient self-consistent implementation. When paired with an appropriate exchange functional, our nonlocal correlation model yields accurate interaction energies of weakly-bound complexes, not only near the energy minima but also far from equilibrium. Our model exhibits an outstanding precision at predicting equilibrium intermonomer separations in van der Waals complexes. It also gives accurate covalent bond lengths and atomization energies. Hence the functional proposed in this work is a computationally inexpensive electronic structure tool of broad applicability., National Science Foundation (U.S.) (NSF CAREER Grant No. CHE-0547877), David & Lucile Packard Foundation (Fellowship)

Published
2011

17. Implementation and assessment of a simple nonlocal van der Waals density functional

Author

Troy Van Voorhis, Oleg A. Vydrov, Massachusetts Institute of Technology. Department of Chemistry, Van Voorhis, Troy, and Vydrov, Oleg A.

Subjects
Cell lists, Chemistry, Van der Waals strain, Van der Waals surface, General Physics and Astronomy, Force field (chemistry), symbols.namesake, Quantum mechanics, symbols, Density functional theory, Van der Waals radius, Statistical physics, Physical and Theoretical Chemistry, van der Waals force, Basis set
Abstract

Recently we developed a nonlocal van der Waals density functional (VV09) that has a simple and well-behaved analytic form. In this article, we report a self-consistent implementation of VV09 with an atom-centered basis set. We compute binding energies for a diverse benchmark set and find that VV09 performs well in combination with Hartree–Fock exchange. We compare VV09 with its precursor, discuss likely sources of inaccuracies in both models, and identify some aspects of the methodology where further refinements are desirable., National Science Foundation (U.S.) (NSF CAREER Grant No. CHE-0547877), David & Lucile Packard Foundation (Fellowship)

Published
2010

18. Exchange and correlation in molecular wire conductance: non-locality is the key

Author

Troy Van Voorhis, Oleg A. Vydrov, Jeremy N. S. Evans, Massachusetts Institute of Technology. Department of Chemistry, Van Voorhis, Troy, Evans, Jeremy S., and Vydrov, Oleg A.

Subjects
Chemistry, General Physics and Astronomy, Conductance, Electronic structure, Electron, Correlation, symbols.namesake, Quantum nonlocality, Molecular wire, Quantum mechanics, symbols, Density functional theory, Physical and Theoretical Chemistry, Physics::Chemical Physics, Hamiltonian (quantum mechanics)
Abstract

We study real-time electron dynamics in a molecular junction with a variety of approximations to the electronic structure, toward the ultimate aim of determining what ingredients are crucial for the accurate prediction of charge transport. We begin with real-time, all electron simulations using some common density functionals that differ in how they treat long-range Hartree–Fock exchange. We find that the inclusion or exclusion of nonlocal exchange is the dominant factor determining the transport behavior, with all semilocal contributions having a smaller effect. In order to study nonlocal correlation, we first map our junction onto a simple Pariser–Parr–Pople (PPP) model Hamiltonian. The PPP dynamics are shown to faithfully reproduce the all electron results, and we demonstrate that nonlocal correlation can be readily included in the model space using the generator coordinate method (GCM). Our PPP-GCM simulations suggest that nonlocal correlation has a significant impact on the I-V character that is not captured even qualitatively by any of the common semilocal approximations to exchange and correlation. The implications of our results for transport calculations are discussed., National Science Foundation (U.S.) (CAREER under Grant No. CHE-0547877), David & Lucile Packard Foundation (Fellowship)

Published
2009

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