### Overview of package shg_int

2-c integral scheme using solid harmonic Gaussians (SHG)

- constants_operator
- constants for the different operators of the 2c-integrals
- construct_shg
- Calculation of the integrals over solid harmonic Gaussian(SHG) functions. Routines for (a|O(r12)|b) and overlap integrals (ab), (aba) and (abb).
- generic_shg_integrals
- Calculation of contracted, spherical Gaussian integrals using the solid harmonic Gaussian (SHG) integral scheme. Routines for the following two-center integrals: i) (a|O(r12)|b) where O(r12) is the overlap, coulomb operator etc. ii) (aba) and (abb) s-overlaps
- generic_shg_integrals_init
- Initialization for solid harmonic Gaussian (SHG) integral scheme. Scheme for calculation of contracted, spherical Gaussian integrals using the solid harmonics. Initialization of the contraction matrices
- s_contract_shg
- Routines for calculating the s-integrals and their scalar derivatives with respect to rab2 over solid harmonic Gaussian (SHG) functions + contraction routines for these integrals i) (s|O(r12)|s) where O(r12) is the overlap, coulomb operator etc. ii) (aba) and (abb) s-overlaps