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A student-led mathematics bootcamp has been designed and implemented to help foster community building, improve confidence in mathematical skills, and provide mathematical resources for incoming physical chemistry doctoral students. The bootcamp is held immediately before the start of the first semester of graduate school and uses an active learning approach to review and practice undergraduate-level mathematics problems over 5 days in small student groups. This work includes the development and presentation of a new, publicly available mathematics curriculum for the bootcamp on select mathematics topics, including calculus, linear algebra, functions, differential equations, statistics, and coding in Python, aiming at improving students' confidence and learning experiences in graduate quantum mechanics and statistical physics courses. Surveys before and after the bootcamp showed an increase in students' confidence in problem-solving in key mathematical areas and social aspects of peer-led group learning. Qualitative and quantitative analyses demonstrate that the bootcamp reduced prior inequities in students' confidence metrics based on gender and mathematical background., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society and Division of Chemical Education, Inc.)

We explore the performance of a recently introduced N5-scaling excited-state-specific second order perturbation theory (ESMP2) on the singlet excitations of the Thiel benchmarking set. We find that, without regularization, ESMP2 is quite sensitive to π system size, performing well in molecules with small π systems but poorly in those with larger π systems. With regularization, ESMP2 is far less sensitive to π system size and shows a higher overall accuracy on the Thiel set than CC2, equation of motion-coupled cluster with singles and doubles, CC3, and a wide variety of time-dependent density functional approaches. Unsurprisingly, even regularized ESMP2 is less accurate than multi-reference perturbation theory on this test set, which can, in part, be explained by the set's inclusion of some doubly excited states but none of the strong charge transfer states that often pose challenges for state-averaging. Beyond energetics, we find that the ESMP2 doubles norm offers a relatively low-cost way to test for doubly excited character without the need to define an active space., (© 2023 Author(s). Published under an exclusive license by AIP Publishing.)

Objectives: The study aims to investigate attention deficit hyperactivity disorder (ADHD) symptoms, gastrointestinal (GI) symptoms, comorbid psychopathology and behaviour problems in children and adolescents with autism spectrum disorder (ASD)., Methods: Parents of 147 children and adolescents with ASD aged 6-18 years completed the Conners 3 Parent-Short Form, Gastrointestinal Symptom Inventory, Behavior Problems Inventory-Short Form and Autism Spectrum Disorder-Comorbid for Children., Results: Fifty-six per cent of children and adolescents had a comorbid diagnosis of ADHD, yet over 70% presented with clinically significant ADHD symptoms. Forty per cent of participants received a diagnosis of ADHD before ASD and 25.6% received a diagnosis of ASD first. Relationships were found between ADHD symptoms and comorbid psychopathology, GI symptoms, and behaviour problems., Conclusions: The outcomes suggest that ADHD is being underestimated as a comorbid disorder of ASD. This may have implications on treatment and interventions for children and adolescents who have a diagnosis of both ASD and ADHD.

We show that by working in a basis similar to that of the natural transition orbitals and using a modified zeroth-order Hamiltonian, the cost of a recently introduced perturbative correction to excited-state mean field theory can be reduced from seventh to fifth order in the system size. The (occupied) 2 (virtual) 3 asymptotic scaling matches that of ground-state second-order Møller-Plesset theory but with a significantly higher prefactor because the bottleneck is iterative: it appears in the Krylov-subspace-based solution of the linear equation that yields the first-order wave function. Here, we discuss the details of the modified zeroth-order Hamiltonian we use to reduce the cost and the automatic code generation process we used to derive and verify the cost scaling of the different terms. Overall, we find that our modifications have little impact on the method's accuracy, which remains competitive with singles and doubles equation-of-motion coupled cluster.