Solidification of the two-dimensional electron gas in high magnetic fields

We present the cubic anharmonic correction to the energy of the magnetophonon wave function for the two-dimensional electron gas in high magnetic fields. An improvement to Lam and Girvin's [Phys. Rev. B 30, 473 (1984)] calculation of the energy of the Wigner solid in high magnetic fields is obtained. By comparing with the fluid energy of variational functions that only work at odd-denominator filling factors, the transition filling factor for melting into the ``odd-denominator'' fluid is changed from 1/6.5 to 1/5.6.