Locating Conical Intersections Using the Quasidegenerate Partially and Strongly Contracted NEVPT2 Methods
Keyword(s):
Conical intersections (CIs) play an important role in photochemistry because they sometimes govern the non-radiative decay process. However, accurate characterizations of CIs are not always straightforward. In this study, analytic gradients and interstate coupling vectors for the quasidegenerate partially and strongly contracted n-electron valence state second-order perturbation theory (QD-PC-NEVPT2 and QD-SC-NEVPT2) were developed and applied to locating CIs of benzene. The pilot application demonstrates that the results of both the methods are similar to the extended multistate complete active space second-order perturbation theory (XMS-CASPT2), while the lack of dynamic electron correlation resulted in a deviation of 0.7 eV.
2020 ◽
2020 ◽
2003 ◽
Vol 107
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pp. 4661-4668
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2019 ◽
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Vol 191
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pp. 507-514
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2016 ◽
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pp. 124115
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2006 ◽
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pp. 234110
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2003 ◽
Vol 107
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pp. 5611-5616
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