& -exf_two*ATAN(x) + exf_half*pi )
PI = 4. * ATAN(1.)
ARG0(I) = ATAN( ARG0(I) )
& MIN( recFac_albNIR*ATAN(albNIR_fHice*hi), 1. _d 0 )
recFac_albNIR = 1. _d 0 / ATAN(albNIR_fHice*0.5 _d 0)
& -two*ATAN(x) + half*pi )
psik=2.*LOG((1.+x)/2.)+LOG((1.+x*x)/2.)-2.*ATAN(x)+2.*ATAN(oneRL)
& - SQRT(3. _d 0)*ATAN( (1.+2.*y)/SQRT(3. _d 0) )
& + 4.*ATAN(oneRL)/SQRT(3. _d 0)