ИСТИНА

Basis sets featuring single exponent 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, following the philosophy of having one single orbital exponent per atomic shell [I.V. Popov, A.L. Tchougreeff, Theor.Chem.Acc,138, 2019, 9 doi: 10.1007/s00214-018-2386-x] by minimizing the total energy (within the ''old'' multiconfigurational self-consistent field - MCSCF approximation) for different spectroscopic states allowed us to extract information for generating obital lobes to describe for instance F-centers in solids, or electrides like cubic Na$_2$He. Within the same {\em philosophy} a slightly different set of exponents (eventually sufficient to describe the entire atomic basis set) can be generated as fits against the experimental spectral data (the ''configuration'' $\prod_{nl}(nl)^m$ energies). Either of the derived basis sets can be fairly dubbed as MAP/МАП (minimal-atomic-primitive/Moscow-Aachen-Paris/Moscou-Aix-la-Chapel-Paris/Москва-Ахен-Париж) basis sets. We show that fundamental properties (radial expectation values, node positions, etc.) of the generated MAP/МАП orbital sets are astonishingly close to those obtained with much larger basis sets known in the literature, without numerical inconsistencies. This is achieved by throurough theoretical analysis of physical relations proven to exist between different primitive-Slater contributions to the MAP/МАП basis states. Possible further applications, trends, and limits are discussed as well.