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For rapid and efficient development of new phosphors, a suitable method that proposes promising candidates is expected to focus time-consuming trial-and-error experiments. A data-driven approach to discover new phosphor materials with a designed luminescence color is demonstrated in this paper. To screen compounds for a desirable luminescence color, a machine learning model has been developed for predicting emission peak wavelengths from a dataset composed of 129 Eu2+-activated phosphors. General-purpose compositional and structural features are used to represent host compounds of phosphors. Bootstrap aggregation with the gradient boosted regression trees method is adopted to obtain high predictive performance and to avoid overfitting. The predictive performance of the machine learning model is estimated to be 25 nm of mean absolute error (MAE) and 33 nm of root mean squared error (RMSE) by 10-fold cross validation. To discover new green-emitting Eu2+-activated phosphors, twenty candidate compounds have been selected to have predicted emission peak wavelengths of about 500–550 nm from a materials database, and the candidates have been synthesized and characterized by experiments. Three new Eu2+-activated phosphors, Li2Ca4Si4O13:Eu2+, Na2Ca2Si2O7:Eu2+, and SrLaGaO4:Eu2+, successfully show green or blue-green emissions as designed., Materials Advances. 4 [1] (2023)231-239

Indirect spin–spin coupling constants are important NMR parameters, indispensable in structure elucidation of organic compounds, and as descriptors of bond character and interactions between coupled atoms. Moreover, the spin–spin coupling phenomenon is the base of numerous nuclear magnetic resonance techniques. The present chapter covers the key work on indirect spin–spin coupling constants published within the period from the end of April 2020 to the end of April 2021. The chapter includes papers concerning theoretical and practical aspects of indirect spin–spin coupling constants, among other calculations of coupling constants, applications of coupling constants in organic chemistry to structure elucidation, and coupling constants across non-covalent bonds.