# www.srampino.com

Index | CV | Publications | Translations | Code | Poetry | Where

Contents

### Waverley

Waverley is: (the hero of the eponymous novel by Sir Walter Scott; Ediburgh's main railway station; and) a gaussian-type orbital (GTO)-based quantum chemistry program package.

Waverley is written in modern Fortran (the F language, http://www.fortran.com/F/F_bnf.html) and uses linear-algebra external libraries BLAS and LAPACK plus the cube file-handling library Cubes.

Waverley is designed in a [object-oriented]-oriented fashion and relies on a core module cgtos.f95 handling cartesian GTOs $g_{i \mapsto l,m,n,\alpha, \boldsymbol{r}_0} (\boldsymbol{r})$ and computing the basic quantities
1. $\langle g_1 | g_2 \rangle$
2. $\langle g_1 | - 1/2\nabla^2 | g_2 \rangle$
3. $\langle g_1 | - Z_c/r_c | g_2 \rangle$
4. $\langle g_1 g_3 | 1/r | g_2 g_4 \rangle$
Integrals are evaluated analytically using explicit formulae rather than more efficient (eg, recursive) schemes.

In the slow-think era, Waverley is a slow (!) program in a sense that it values readability over efficiency and learning over production.

Present features of Waverley are:
• analytic integrals over contracted cartesian GTOs
• closed-shell restricted-Hartree-Fock (RHF) self-consisted-field (SCF) procedure
• SCF guess: one-electron Hamiltonian
• SCF convergence: level shifting
• configuration file-handled output
• all matrices and vectors involved
• orbitals and densities as .cube files
Waverley is under development and will (hopefully) be made available soon. For any interest or enquiries please do not hesitate to contact moc.onipmars@ofni.

### Cubes

Cubes is a toolkit for manipulating 'cube' files of the Gaussian cube file format (.cub, .cube extensions supported by most electronic structure or visualization packages). Cube files store the values of a real function of three coordinates (eg, orbitals or electron densities) mapped onto an evenly spaced 3D grid associated to a molecular system in a given nuclear configuration (geometry).

Cubes is both a library and a program suite. The library provides a 'cube' data type and procedures for operating on it (such as read, write, access data, add, integrate, etc). The program suite is built on top of the library and provides ready-to-use commands for a few common basic operations (addition, subtraction, integration, etc).

The ready-to-use commands are meant to be executed from command line taking as arguments directly the cube files. Eg, given two cube files A.cube and B.cube storing the electron densities of an A and a B system respectively, the command 'cubeadd A.cube B.cube A+B.cube' will output an A+B.cube file storing the superposition of such densisties for a molecular system made up of the A and B fragments.

Cubes is entirely written in modern Fortran (F standard: http://www.fortran.com/F/F_bnf.html) and needs a mimimal set of requirements: a Fortran compiler and a Unix-like shell terminal. Cubes is under active development and is intended to evolve according to its users' needs and feedbacks.

### Pestk

Pestk (potential-energy-surface toolkit) is a program package for constructing and inspecting potential energy surfaces (PESs) of few-atom reactive systems.

Pestk is written in modern Fortran (F standard: http://www.fortran.com/F/F_bnf.htm l) and is under development.

At present, the SRBO program is made available (download here the archive srbo.tgz including a read-me file, a Makefile and the Fortran sources).

SRBO constructs space-reduced bond-order (SRBO) grids for optimal configuration-space sampling of a diatom starting from input parameters re, De, ke, Vfact, Vthrs and the desired couple (Nr, Na).

(More details to come...).

(c) Sergio Rampino 2015-8.

Last update Tue May 8 17:37:15 CEST 2018