buffer2(i+imax*(3-1)) = buffer2(i+imax*(3-1)) + buffer1(1+(i-1)*kmax) * sphi_b(1,3+s_offset_b1)
buffer2(i+imax*(1-1)) = buffer2(i+imax*(1-1)) + buffer1(2+(i-1)*kmax) * sphi_b(2,1+s_offset_b1)
buffer2(i+imax*(2-1)) = buffer2(i+imax*(2-1)) + buffer1(3+(i-1)*kmax) * sphi_b(3,2+s_offset_b1)
