Modules

Basis ingestion API bridging external handles to OpenQP basis_set. internal basis_set (cartesian AO layout), normalizes primitives, and prints a compact basis/ECP summary to the log.

C-binding wrapper for the MO/DM projection routine.

Runtime control of BLAS-library internal threading

Bragg-Slater radii for determining the relative size of the polyhedra in the polyatomic integration scheme

Cartesian -> pure spherical-harmonic (c2s) transforms for shells.

@brief Native coupled-perturbed Hartree-Fock / Kohn-Sham (CPHF/CPKS) solver for closed-shell (RHF/RKS) references.

Douglas-Kroll scalar relativistic correction to the one-electron Hamiltonian

@brief Two-electron derivative-Fock contraction tr(M . F^x[P]) for the CPHF nuclear right-hand side, built natively on top of the validated 2e gradient driver (grd2_driver) with no changes to the Rys internals and no libint.

Module for calculating state overlaps and derivative coupling matrix elements

Module to process stored SCF guess data in JSON format.

This module contains subroutines for 1-electron integrals

MINAO atomic-density lookup table.

Helper functions and data blocks needed

Cross-iteration cache of the collocation matrix Phi (AO values and derivatives on the quadrature grid) used by the DFT XC build.

Gauss-Hermite quadrature used in one-electron integral code

Standalone Moller-Plesset second-order (MP2) ground-state correlation

The initialization of Open Quantum Platform (OpenQP = OQP in source code level) It does: 1) Setting up the log file 2) Printing out author information 3) Printing out the basic information regarding OS, date, HW Specs.

buffer_types defines a list of data types used in parallel communication. Each entry specifies: (1) A human-readable name for the data type, (2) The corresponding MPI data type for communication, (3) The Fortran data type (with the appropriate kind), (4) The array rank or shape (e.g., scalar, 1D, 2D, etc.). These types are used for creating allreduce/bcast buffers in MPI operations.

@author Vladimir Mironov

Cached canonical orthogonalizer Q = S^(-1/2) without caching it is computed (an O(nbf^3) eigendecomposition) at least twice per run. The cache lives in the tagarray under OQP_QMAT and is invalidated by int1e whenever the overlap matrix is recomputed (new geometry or basis set).

Radial superposition-of-atomic-potentials (SAP) lookup table.

Trust-region augmented-Hessian (TRAH) SCF solver. augmented-Hessian/level-shift lineage traces to Bacskay, Chem. Phys. 61, 385 (1981). Selected by control%trh_impl = 1. Reuses the physics callbacks already provided by the trah_converger (calc_g_h, calc_h_op, rotate_orbs) plus calc_fock/get_ab_initio_density/compute_energy -- only the optimization shell is implemented here.