Questions tagged [full-configuration-interaction]

For questions about FCI (full configuration interaction) calculations.

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8
votes
3answers
129 views

What are the advantages of the Davidson diagonalization method over other sparse matrix diagonalization methods?

I am interested to understand the advantages of the Davidson diagonalization method over other sparse matrix diagonalization routines. For instance, Intel MKL.
6
votes
2answers
438 views

Analytic Hessian at the level of full CI?

This is a follow-up question to my previous question: Computing analytic derivatives of molecular Hamiltonians obtained from solving Hartree-Fock equations. After looking at various quantum chemistry ...
9
votes
1answer
94 views

What do the parameters at the top of an FCIDUMP file mean?

A while ago I wrote a simple program that takes in an FCIDUMP file (generated by MOLRPO) and can determine matrix elements (or ...
9
votes
1answer
177 views

How to calculate FCI matrix elements from an FCIDUMP file

I'm interested in writing a simple program (as an exercise) that takes an FCIDUMP file (e.g. from a Molpro calculation) and can determine FCI matrix elements (e.g. to construct the entire FCI matrix ...
26
votes
1answer
410 views

How accurate are the most accurate calculations?

Taking into account the fact that the theory of quantum gravity does not exist and the QED calculations are not possible for most realistic chemical systems, what levels of accuracy can we expect from ...
14
votes
1answer
235 views

Orbitals in full CI and DFT with true functional

Is there any paper that proves/disproves that the occupied orbitals obtained using full Configuration Interaction (CI) are the same as the orbitals obtained using DFT (assuming we use the exact ...