Questions tagged [multi-reference]
Apply this tag to questions about methods that use multiple determinants to construct the wave function, e.g. MCSCF, MR-PT, CASSCF, MR-CI, etc., questions about chemical systems that might require these methods.
5 questions with no upvoted or accepted answers
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What is the theoretical justification for state averaging in SA-CASSCF?
According to the molpro manual, section 7.3:
In order to compute excited states it is usually best to optimize the
energy average for all states under consideration. This avoids
root-flipping ...
- 1,026
4
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How can I save and read the CI vector during CASSCF calculations in Gaussian?
I have searched through the GAUSSIAN 16 manual and have not been able to solve these two related issues:
(1) I want to be able to save the CI vector and load it as an initial guess for a different ...
- 1,026
3
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Is configuration interaction able to produce degenerate ground states?
I am new to multi-determinant theories. What motivates me in asking this question is the following observation: Consider the Dyson orbital of a $\ce{CO2}$ molecule whose axis is parallel to the $z$ ...
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Charge Transfer and Multireference Methods
I have read in literature that systems that exhibit "high charge-transfer character" are best treated using multireference/multiconfigurational methods. Why is that? What makes such a system ...
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How can I understand if my system has degenerate electronic configuration?
How can I understand if my system has degenerate electronic configuration?
I'm running some post-HF methods and in the meanwhile try to understand which is the most accurate method for my system. ...
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