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Main Authors: Tran, Nhan Tri, Tran, Lan Nguyen
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2411.00251
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author Tran, Nhan Tri
Tran, Lan Nguyen
author_facet Tran, Nhan Tri
Tran, Lan Nguyen
contents Intermolecular charge-transfer (xCT) excited states important for various practical applications are challenging for many standard computational methods. It is highly desirable to have an affordable method that can treat xCT states accurately. In the present work, we extend our self-consistent perturbation methods, named one-body second-order Møller-Plesset (OBMP2) and its spin-opposite scaling variant, for excited states without additional costs to the ground state. We then assessed their performance for the prediction of xCT excitation energies. Thanks to self-consistency, our methods yield small errors relative to high-level coupled cluster methods and outperform other same scaling ($N^5$) methods like CC2 and ADC(2). In particular, the spin-opposite scaling variant (O2BMP2), whose scaling can be reduced to $N^4$, can even reach the accuracy of CC3 ($N^7$) with errors less than 0.1 eV. This method is thus highly promising for treating xCT states in large compounds vital for applications.
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spellingShingle Attaining high accuracy for charge-transfer excitations in non-covalent complexes at second-order perturbation cost: the importance of state-specific self-consistency
Tran, Nhan Tri
Tran, Lan Nguyen
Chemical Physics
Intermolecular charge-transfer (xCT) excited states important for various practical applications are challenging for many standard computational methods. It is highly desirable to have an affordable method that can treat xCT states accurately. In the present work, we extend our self-consistent perturbation methods, named one-body second-order Møller-Plesset (OBMP2) and its spin-opposite scaling variant, for excited states without additional costs to the ground state. We then assessed their performance for the prediction of xCT excitation energies. Thanks to self-consistency, our methods yield small errors relative to high-level coupled cluster methods and outperform other same scaling ($N^5$) methods like CC2 and ADC(2). In particular, the spin-opposite scaling variant (O2BMP2), whose scaling can be reduced to $N^4$, can even reach the accuracy of CC3 ($N^7$) with errors less than 0.1 eV. This method is thus highly promising for treating xCT states in large compounds vital for applications.
title Attaining high accuracy for charge-transfer excitations in non-covalent complexes at second-order perturbation cost: the importance of state-specific self-consistency
topic Chemical Physics
url https://arxiv.org/abs/2411.00251