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36 #include "gmx_lapack.h"
39 F77_FUNC(slasd5,SLASD5)(int *i__,
47 float b, c__, w, del, tau, delsq;
54 del = d__[2] - d__[1];
55 delsq = del * (d__[2] + d__[1]);
57 w = *rho * 4. * (z__[2] * z__[2] / (d__[1] + d__[2] * 3.) - z__[1] *
58 z__[1] / (d__[1] * 3. + d__[2])) / del + 1.;
60 b = delsq + *rho * (z__[1] * z__[1] + z__[2] * z__[2]);
61 c__ = *rho * z__[1] * z__[1] * delsq;
63 tau = c__ * 2. / (b + sqrt(fabs(b * b - c__ * 4.)));
65 tau /= d__[1] + sqrt(d__[1] * d__[1] + tau);
66 *dsigma = d__[1] + tau;
69 work[1] = d__[1] * 2. + tau;
70 work[2] = d__[1] + tau + d__[2];
72 b = -delsq + *rho * (z__[1] * z__[1] + z__[2] * z__[2]);
73 c__ = *rho * z__[2] * z__[2] * delsq;
76 tau = c__ * -2. / (b + sqrt(b * b + c__ * 4.));
78 tau = (b - sqrt(b * b + c__ * 4.)) / 2.;
81 tau /= d__[2] + sqrt(fabs(d__[2] * d__[2] + tau));
82 *dsigma = d__[2] + tau;
83 delta[1] = -(del + tau);
85 work[1] = d__[1] + tau + d__[2];
86 work[2] = d__[2] * 2. + tau;
90 b = -delsq + *rho * (z__[1] * z__[1] + z__[2] * z__[2]);
91 c__ = *rho * z__[2] * z__[2] * delsq;
94 tau = (b + sqrt(b * b + c__ * 4.)) / 2.;
96 tau = c__ * 2. / (-b + sqrt(b * b + c__ * 4.));
98 tau /= d__[2] + sqrt(d__[2] * d__[2] + tau);
99 *dsigma = d__[2] + tau;
100 delta[1] = -(del + tau);
102 work[1] = d__[1] + tau + d__[2];
103 work[2] = d__[2] * 2. + tau;