[en] For the elements: H, B, C, N, O, F, Na, Mg, Al, Si, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni and Pb a 26 neutron group library of cross sections has been calculated for energies ranging from 14 MeV down to 0.215 eV. The following cross sections have been calculated: SR(J) - removal, STR(J) -transport and SL(J,L) - slowing down from the energy group J down to the group J+L. These group cross sections have been calculated using the algorithms proposed by Kreft starting from the microscopic cross section library of Abagyan et al. The library is in the form of the program NEWCROSS.BAS written in BASIC for IBM PC microcomputers. This library is used to calculate the slowing down parameters of rocks using the programs SLOWDOWN.BAS, SLOWN1.BAS or SLOWN2.BAS. (author)