;                                 The map p(o) was calculated with coefficients
                                  2F(o) - F(c) and with phase alpha(c). F(o)
                                  are the observed structure-factor amplitudes,
                                  F(c) are the amplitudes calculated from the
                                  current model and alpha(c) are the phases
                                  calculated from the current model.
                                  The map p(c) was calculated in program O using
                                  a Gaussian distribution function around the
                                  atoms in the current model.
                                  Map grid points within 1.5 A of the
                                  designated atoms were included in the
                                  calculation.
;

;                                 The map p(o) was calculated with coefficients
                                  F(o) and with phase alpha(c). F(o) are the
                                  observed structure-factor amplitudes, and
                                  alpha(c) are the phases calculated from the
                                  current model.
                                  The map p(c) was calculated with coefficients
                                  F(c) and with phases alpha(c). F(c) and
                                  alpha(c) are the structure-factor amplitudes
                                  and phases, respectively, calculated from the
                                  current model.
                                  Map grid points within a van der Waals radius
                                  of the designated atoms were included in the
                                  calculation.
;