The Hartree-Fock-Roothaan ab initio self-consistent average field method has been used in calculating the pair interaction potentials for atoms in the P2 and GaP molecules. The gallium and phosphorus atoms are considered in their ground states. The calculations agree well with experiment.When phosphorus evaporates from solution in molten gallium under Langmuir conditions, the direct molecular beam contains only P2 molecules and gallium atoms [1], which has not been given a suitable theoretical explanation, in spite of its practical importance. It is therefore necessary to simulate the interactions of the atoms and molecules in the vapor above the liquid. If one knows the corresponding pair interaction potentials, the simulation can be based on molecular dynamics [2,3], and the method is based on selecting the pair interaction potential, for which one often uses a Morse potential:( 1) in which D is the molecular dissociation energy, R0 the equilibrium interatomic distance, R the distance between the atoms, and a a parameter.Information on pair interaction potentials can be obtained by measuring virial coefficients, critical gas and vapor parameters, saturation vapor pressures, and other properties affected by the interaction, i.e., by experiment. The set of such data provides atomic interaction potential curves, with the distance between the atoms the independent parameter.Our purpose has been to use nonempirical quantum-chemical calculations on the molecular orbitals MO for the diatomic molecules P2 and GaP to determine the parameters of the pair interaction potential of (1) for Pe and GaP.We used the Hartree-Fock-Roothaan self-consistent field method [4,5] in a nonempirical calculation on the electronic structures of Pe and GaP. The molecular orbitals were represented as linear combinations of the atomic orbitals AO. We considered the singlet states of the molecules ( l + Zg state for P2 and 1 ]~+ state for GAP). We used the one-determinant and adiabatic approximations to determine the dependence of the total energy for each molecule on the interatomic distance. The one-determinant approximation is applicable for small changes from the equilibrium value in the interatomic distance. The calculations were performed in a gaussian basis. The Hartree-Fock-Roothaan method approximates the complete multielectron wave function for the system as an antisymmetrized product of one-electron functions q0p, which are called molecular orbitals [4,5]. It is in which N is the number of electrons.The following is the mean total electron energy (neglecting the nuclear interaction):Voronezh State Technical University, Voronezh.

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The article considers the method of determining the geometric parameters of technological equipment with the use of automated total stations. It analyses the results of production work to determine the spatial position of the equipment. It is noted that under certain conditions, the use of total stations allows determining the spatial position of control points on the equipment with the necessary accuracy. The preliminary investigations of accuracy by all modes of measurements distances and angles in the laboratory conditions and conditions, as close as possible to real are recommended. To perform measurements at short distances, an improved measurement technique is proposed. The peculiarity of the proposed technique is that during measurements it is proposed to use simultaneously a high-precision automated total station and a high-precision digital level. The article gives the results of measurements. It is established that the considered technique makes it possible to increase the accuracy of determining the control points’ marks on the equipment.

When performing high-precision leveling in an operating industrial enterprise the sighting beam often to pass through directed streams of hot air. Laboratory researches were carried out using a DiNi 0.3 digital level, an H-05 optical level, and a Leica TCRP 1201+ total station. During the intersection of the sighting beam and hot air stream, observed of the blurring staff image, an increase in the standard deviation of taking a reading along the staff by 2-3 times. The stream of heated air leads to the appearance of a systematic error in taking readings along the staff: when working with a digital level, the readings are less than the true value, and when working with an optical level and total station - more. It is expected that the average of the elevation values obtained by different types of levels will be more free from the systematic influence of refraction.