Introduction

ATOMS is a package for developing new type of sets of atomic orbitals suitable for semiempirical quantum chemistry written by Ilya V. Popov and Andrei L. Tchougréeff.
Programming is based on our library CARTESIUS_FORT.
The basis sets derived with use of the ATOMS program have proper nodal structure and simple functional form of a product of a polynomial times an exponential and depend on the set of exponents whereas the coefficients of the polynomial (and thus the positions of the radial nodes) are determined by the orthonormality conditions for the orbitals. The derived sets represent atomic properties with reasonable accuracy, Originally, so defined basis sets dubbed as MAP/МАП (minimal atomic primitive / Moscow–Aachen–Paris / Moscou–Aix-la-Chapelle–Paris / Москва–Ахен–Париж) were obtained for the 2nd-row elements either by minimization of their ground state energy or by extracting from atomic spectra.

Later the MAP basis sets featuring single exponents for each of the nl subshells and orthogonality of the radial parts for different values of n within the same l have been generated for a large part of the Periodic Table in cooperation with Prof. P. Reinhardt (Sorbonne, Paris).

Resources: Pictures of the radial functions of the MAP basis sets are available on-line. More services to follow.

Publications: when using this service please quote

1. I.V. Popov, A.L. Tchougréeff. Atomic orbitals revisited: generalized hydrogen-like basis sets for 2nd-row elements (2019) Theoretical Chemistry Accounts 138 (1):9 DOI: 10.1007/s00214-018-2386-x.
2. Peter Reinhardt, Ilya Popov, Andrei L. Tchougréeff