A great improvement on a previous work (Phys. Rev. B48 (1993) 14067) has been made. By taking intoaccount all the irreducible representations and their components in the electron-phonon interaction (EPI) as well as allthe levels and the admixtures of basic wavefunctions within d3 electronic configuration, the values of all the parametersin the expressions of thermal shift (TS) and thermal broadening (TB) from EPI for the ground level, R level and R lineof MgO:V2+ have microscopically been evaluated; and then, both the TS and TB of R line and various contributions tothem have uniformly been calculated. The results are in very good agreement with the experimental data. It is foundthat all the three terms of TS from EPI are red shifts; the term of the contribution to TS from thermal expansion is blueshift. The Raman term is the largest, and the other terms are also important for TS. The R-line TS of MgO:V2+ comesfrom the first-order term of EPI. The elastic Raman scattering of acoustic phonons plays a dominant role in R-line TBof MgO:V2+. For calculations of both the TS and TB, it is very important to take into account all the admixtures ofwavefunctions.