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	3965	August 12, 2019
Welcome to the PSI4 Forum!	1	23358	July 16, 2015
Simple CCSD calculation fails for a large molecule build	2	18	November 30, 2024
Number of Basis Functions is Mismatched/Inconsistent!	2	24	November 19, 2024
Why does nuclear_repulsion_energy depend on the external electric field?	1	18	November 19, 2024
Does Psi4 Support Complex SCF?	1	22	November 18, 2024
My custom code isn't passing tests, help!	5	62	November 18, 2024
Dipole moment finite-field computation Psi4Education	1	24	November 15, 2024
Problem with dftd4 installation build	3	58	November 9, 2024
How to compute the SCF unrelaxed energy?	2	41	November 9, 2024
Spherical averaging of occupied orbitals on atoms	5	917	January 20, 2021
MP2 polarizability using finite field	4	1739	November 4, 2024
What's wrong with my attempt to test Brillouin's Theorem?	2	33	October 31, 2024
What's wrong with my attempt to reproduce the dipole moment?	1	32	October 31, 2024
Why am I getting strange results for transition metals in Psi4 1.5?	16	48	October 29, 2024
Where is psi4_dev located?	1	16	October 28, 2024
Multi-threading two-electron integrals	0	20	October 27, 2024
Installtion of PSI4 Psi4conda-1.9.1-py38-Linux-x86_64.sh Geometry Optimization	0	22	October 21, 2024
First order hyperpolarizability with DFT	0	25	October 19, 2024
RuntimeError when setting custom Ca and Cb matrices in Wavefunction	1	31	October 17, 2024
Mixed RHF and ROHF	2	31	October 15, 2024
Psimrcc energy calculation not right for symmetry c1	2	36	October 11, 2024
Offline instalation build	0	22	October 9, 2024
Is it required to run fsapt.py after FISAPT SAPT	0	19	October 8, 2024
Attempting to build on HPC - Eigen issues build	0	26	October 8, 2024
What meanings do the value "Total E, Thermal(internal) energy at 298.15 [K]" have?	2	38	October 6, 2024
Normalization of density in Cubeprop	4	56	October 4, 2024
Suggestions for HPC installation? build	2	78	September 29, 2024
Error in dihedral scan	0	17	September 24, 2024
Charge and multiplicity for non neutral fragments	1	40	September 24, 2024

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…