Psi4 – Open-Source Quantum Chemistry

Topic	Replies	Views	Activity
Making Topics that Get Answered Most questions that are answered on the Psi4 Forums are answered by a small group of developers and powerusers. Their time and energy is divided between their own research, further Psi development, and helping users. Acc…	2	2696	August 12, 2019
Welcome to the PSI4 Forum!	1	22254	July 16, 2015
Using existing JK object in psi4numpy	0	9	March 27, 2023
Memory/Core effect on reproducing calculations to higher precision	2	21	March 27, 2023
How to pass an array in Psi4 plugin development? Developer News & Discussion	1	33	March 27, 2023
FROZEN_DISTANCE command - still working?	5	33	March 27, 2023
Frequency calculation extremely slow	6	77	March 25, 2023
Out of memory using PCM model: Geom. optimization of lithiated ethylene carbonate Geometry Optimization	1	29	March 24, 2023
Error after using pk = Psikit()	1	22	March 24, 2023
Calculated of energy decomposition with Not converge SCF Developer News & Discussion	4	41	March 20, 2023
Psi4 cartesian coordinates precision from same starting point geometry Geometry Optimization	10	96	March 16, 2023
Vibrational Hamiltonian	1	28	March 16, 2023
SCF calculations of an optimized geometry is slow to converge	9	95	March 14, 2023
SAPT0, open-shell and closed-shell intermolecular interaction; DFHelper:get tensor:read error	2	111	March 11, 2023
Modified cc-pv5z basis set in PSI4?	3	58	March 7, 2023
"Maximum dynamic_level reached" Geometry Optimization	6	139	February 27, 2023
Fatal Error: Cannot set element X since there are only X elements	19	161	February 25, 2023
Integral transformation using abelian symmetry	2	43	February 25, 2023
More detailed explanation of guess_mix	6	64	February 24, 2023
SCF iterations do not converge in water - Zn2+ system	3	58	February 24, 2023
Frequency calculation on an optimized geometry + thermodynamic analysis	5	87	February 22, 2023
GDMA problem: "CC" density not found	0	31	February 17, 2023
Reallocation of matrix object 'Ca' with new matrix of different dimension	3	44	February 15, 2023
Error with Pb scf calculation	8	230	February 9, 2023
Constraining spins to an atom	12	159	February 3, 2023
Problem with Psi4 installation	1	88	January 25, 2023
Different energies and much longer time for DKH2 comparing with molpro	6	96	March 26, 2023
Psi4 exitfunctions error messages at the end of multi-step parallel calculation	3	100	January 23, 2023
Lmax_exceeded error for optimizing single Zinc ion	5	116	January 22, 2023
FIXED_DIHEDRAL is not a valid option	5	118	January 20, 2023

Making Topics that Get Answered

Most questions that are answered on the Psi4 Forums are answered by a small group of developers and powerusers. Their time and energy is divided between their own research, further Psi development, and helping users. Acc…