A variational procedure for the solution of the Boltzmann equation with a n arbitrary number of variational parameters is developed. In the frame of the method it is possible to carry out t h e optimization of trial function, as well as to check the convergence of the solution. It is shown that. in semimetals the probability matrix of charge carrier scattering on acoustic phonons entering the expression for the collision operator has a non-diagonal form in the coordinate system of the effective mass tensor. General expressions are obtained for the transport coefficients allowing to determine their numerical values.PaapaBo~ntra BapHaqnoman npouenypa pelrremn KHtIeTwIec~oro ypani~eiiuc! Gontu-

The possibility of the commutational effect (CE) of thermo-e.m.f. a t different orientations of the magnetic field and temperature gradient is investigated in the frames of the variational method of calculation of transport coefficients. It is found that for some of the components of the magnetothermo-e.m.f. tensor CE appears only in strong and intermediate fields.

A comparison of the experimental and calculated data for bhe transport coefficients in bismuth obtained on the basis of the variational microscopic model is carried out. The assumption about the predomination of carrier scattering on acoustic phonons in bismuth is confirmed. The values of deformation potential constants are calculated for a wide range of temperatures. The temperature and magnetic field dependences of transport coefficients in the wide range of temperatures and magnetic fields determined by variational method, completely reproduce the experimental data.

The galvanomagnetic coefficients of arsenic are calculated by means of a variational method taking intravalley scattering of charge carriers on longwave acoustic phonons into account. The experimental data of galvanomagnetic phenomena in weak magnetic fields are processed with the help of the formulae obtained and the constants of deformation potentials of electrons and holes are calculated in a wide temperature range (77 to 305 K). B npennonolrceaam BKyTpmnonHHHoro paccemm HocnTeneii s a p~n a Ha EJIMHHOBOZ-BapHaUHOHHbIM MeTOAOM BbIYEZCJIeHbI I' aJIbBaHOMaFHUTHbIe K03@@HqHeHTbI MbILUbFIIFa HOBbIX aKyCTHYeCKHX @OHOHBX. c n O M O~b E 0 IlOJIyYeHHbIX @OpMyn o 6 p a 6 o~a~~ 3HC-IIepHMeHTaJlbHbIe AaHHbIe no FaJIbBaHOMarHHTHbIM FIBJIeHHFIM B c n a 6~x MarHElTHbIX nOJIRX H BbIYEZCJIeHbI KOHCTaHTbI ae@OPMaqHOHHbIX IIOTeHUHaJIOB 3neKTPOHOB H HbIPOIF B InHpoKoZi o 6 n a c~~ TeMnepaTyp: 77 no 305 K.

The thermopower and the thermomagnetic power a t low temperatures (4.5 to 77 K) is investigated in As,Sbl-z (z 5 0.3) alloys. Peculiarities of the thermopower are observed, which are associated with the dragging of electrons by phonons. In magnetic fields B > 5 T the Shubnikovde Haas type quantum oscillation of the thermomagnetic power is displaid. It is established, that the As,Sbl-, (5 5 0.2) alloys are semimetals, and the overlapping of the energy extrema of L electrons and H holes increases, when arsenic is added to alloys. B CnJIaBax .4s,Sbl-z (X 5 0,3) MCCJleaOBaHbI TepM03AC M MarHHTOTepMO3aC IIpH HM3KMX