On semiempirical determination of vibrational-rotational parameters of diatomic molecules. Optimal sets of constants for asup(3) 9sub(g)sup(+), esup(3)9sub(u)sup(+), dsup(3)PIsub(u)sup(+-), fsup(3)9sub(u)sup(+) states of H2

Possibility of description of electron-vibrational-rotational terms of diatomic molecules with the use of a limited set of molecular constants is investigated. It is shown using the lowest triplet H2 states as an example, that when determining a totality of vibrational-rotational constants of the given electronic state and their covariance matrix, it is necessary to take into account the specific character of the physical problem, for which these constants may be used. The obtained optimal sets of constants are essentially different from the available literature ones. Reasons of disagreement are discussed