  We revisit the pressure-induced metal-insulator-transition of solid hydrogen
by means of variational quantum Monte Carlo simulations based on the
antisymmetric shadow wave function. In order to facilitate studying the
electronic structure of large-scale fermionic systems, the shadow wave function
formalism is extended by a series of technical improvements, such as a revised
optimization method for the employed shadow wave function and an enhanced
treatment of periodic systems with long-range interactions. It is found that
the superior accuracy of the antisymmetric shadow wave function results in a
significantly increased transition pressure.
