subroutine gfssflx::frh2o	(	real (kind=kind_phys), intent(in)	tkelv,
		real (kind=kind_phys), intent(in)	smc,
		real (kind=kind_phys), intent(in)	sh2o,
		real (kind=kind_phys), intent(in)	smcmax,
		real (kind=kind_phys), intent(in)	bexp,
		real (kind=kind_phys), intent(in)	psis,
		real (kind=kind_phys), intent(out)	liqwat
	)

New version (June 2001): much faster and more accurate Newton iteration achieved by first taking log of eqn cited above – less than 4 (typically 1 or 2) iterations achieves convergence. Also, explicit 1-step solution option for special case of paramter ck=0, which reduces the orginal implicit equation to a simpler explicit form, known as the "flerchinger eqn". Improved handling of solution in the limit of freezing point temperature t0.

Referenced by snksrc().