slasd4.c

最著名最快的分子模拟软件

	i__1 = iip1;
	for (j = *n; j >= i__1; --j) {
	    temp = z__[j] / (work[j] * delta[j]);
	    phi += z__[j] * temp;
	    dphi += temp * temp;
	    erretm += phi;
	}

	w = rhoinv + phi + psi;

	swtch3 = 0;
	if (orgati) {
	    if (w < 0.) {
		swtch3 = 1;
	    }
	} else {
	    if (w > 0.) {
		swtch3 = 1;
	    }
	}
	if (ii == 1 || ii == *n) {
	    swtch3 = 0;
	}

	temp = z__[ii] / (work[ii] * delta[ii]);
	dw = dpsi + dphi + temp * temp;
	temp = z__[ii] * temp;
	w += temp;
	erretm = (phi - psi) * 8. + erretm + rhoinv * 2. + fabs(temp) * 3. + 
		fabs(tau) * dw;

	if (fabs(w) <= eps * erretm) {
	    goto L240;
	}

	if (w <= 0.) {
	    sg2lb = (sg2lb > tau) ? sg2lb : tau;
	} else {
	    sg2ub = (sg2ub < tau) ? sg2ub : tau;
	}

	++niter;
	if (! swtch3) {
	    dtipsq = work[ip1] * delta[ip1];
	    dtisq = work[*i__] * delta[*i__];
	    if (orgati) {
		d__1 = z__[*i__] / dtisq;
		c__ = w - dtipsq * dw + delsq * (d__1 * d__1);
	    } else {
		d__1 = z__[ip1] / dtipsq;
		c__ = w - dtisq * dw - delsq * (d__1 * d__1);
	    }
	    a = (dtipsq + dtisq) * w - dtipsq * dtisq * dw;
	    b = dtipsq * dtisq * w;
	    if ( fabs(c__)<GMX_FLOAT_MIN) {
		if ( fabs(a)<GMX_FLOAT_MIN) {
		    if (orgati) {
			a = z__[*i__] * z__[*i__] + dtipsq * dtipsq * (dpsi + 
				dphi);
		    } else {
			a = z__[ip1] * z__[ip1] + dtisq * dtisq * (dpsi + 
				dphi);
		    }
		}
		eta = b / a;
	    } else if (a <= 0.) {
		eta = (a - sqrt(fabs(a * a - b * 4. * c__))) / (c__ * 2.);
	    } else {
		eta = b * 2. / (a + sqrt(fabs(a * a - b * 4. * c__)));
	    }
	} else {

	    dtiim = work[iim1] * delta[iim1];
	    dtiip = work[iip1] * delta[iip1];
	    temp = rhoinv + psi + phi;
	    if (orgati) {
		temp1 = z__[iim1] / dtiim;
		temp1 *= temp1;
		c__ = temp - dtiip * (dpsi + dphi) - (d__[iim1] - d__[iip1]) *
			 (d__[iim1] + d__[iip1]) * temp1;
		zz[0] = z__[iim1] * z__[iim1];
		if (dpsi < temp1) {
		    zz[2] = dtiip * dtiip * dphi;
		} else {
		    zz[2] = dtiip * dtiip * (dpsi - temp1 + dphi);
		}
	    } else {
		temp1 = z__[iip1] / dtiip;
		temp1 *= temp1;
		c__ = temp - dtiim * (dpsi + dphi) - (d__[iip1] - d__[iim1]) *
			 (d__[iim1] + d__[iip1]) * temp1;
		if (dphi < temp1) {
		    zz[0] = dtiim * dtiim * dpsi;
		} else {
		    zz[0] = dtiim * dtiim * (dpsi + (dphi - temp1));
		}
		zz[2] = z__[iip1] * z__[iip1];
	    }
	    zz[1] = z__[ii] * z__[ii];
	    dd[0] = dtiim;
	    dd[1] = delta[ii] * work[ii];
	    dd[2] = dtiip;
	    F77_FUNC(slaed6,SLAED6)(&niter, &orgati, &c__, dd, zz, &w, &eta, info);
	    if (*info != 0) {
		goto L240;
	    }
	}

	if (w * eta >= 0.) {
	    eta = -w / dw;
	}
	if (orgati) {
	    temp1 = work[*i__] * delta[*i__];
	    temp = eta - temp1;
	} else {
	    temp1 = work[ip1] * delta[ip1];
	    temp = eta - temp1;
	}
	if (temp > sg2ub || temp < sg2lb) {
	    if (w < 0.) {
		eta = (sg2ub - tau) / 2.;
	    } else {
		eta = (sg2lb - tau) / 2.;
	    }
	}

	tau += eta;
	eta /= *sigma + sqrt(*sigma * *sigma + eta);

	prew = w;

	*sigma += eta;
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    work[j] += eta;
	    delta[j] -= eta;
	}

	dpsi = 0.;
	psi = 0.;
	erretm = 0.;
	i__1 = iim1;
	for (j = 1; j <= i__1; ++j) {
	    temp = z__[j] / (work[j] * delta[j]);
	    psi += z__[j] * temp;
	    dpsi += temp * temp;
	    erretm += psi;
	}
	erretm = fabs(erretm);

	dphi = 0.;
	phi = 0.;
	i__1 = iip1;
	for (j = *n; j >= i__1; --j) {
	    temp = z__[j] / (work[j] * delta[j]);
	    phi += z__[j] * temp;
	    dphi += temp * temp;
	    erretm += phi;
	}

	temp = z__[ii] / (work[ii] * delta[ii]);
	dw = dpsi + dphi + temp * temp;
	temp = z__[ii] * temp;
	w = rhoinv + phi + psi + temp;
	erretm = (phi - psi) * 8. + erretm + rhoinv * 2. + fabs(temp) * 3. + 
		fabs(tau) * dw;

	if (w <= 0.) {
	    sg2lb = (sg2lb > tau) ? sg2lb : tau;
	} else {
	    sg2ub = (sg2ub < tau) ? sg2ub : tau;
	}

	swtch = 0;
	if (orgati) {
	    if (-w > fabs(prew) / 10.) {
		swtch = 1;
	    }
	} else {
	    if (w > fabs(prew) / 10.) {
		swtch = 1;
	    }
	}

	iter = niter + 1;

	for (niter = iter; niter <= 20; ++niter) {

	    if (fabs(w) <= eps * erretm) {
		goto L240;
	    }

	    if (! swtch3) {
		dtipsq = work[ip1] * delta[ip1];
		dtisq = work[*i__] * delta[*i__];
		if (! swtch) {
		    if (orgati) {
			d__1 = z__[*i__] / dtisq;
			c__ = w - dtipsq * dw + delsq * (d__1 * d__1);
		    } else {
			d__1 = z__[ip1] / dtipsq;
			c__ = w - dtisq * dw - delsq * (d__1 * d__1);
		    }
		} else {
		    temp = z__[ii] / (work[ii] * delta[ii]);
		    if (orgati) {
			dpsi += temp * temp;
		    } else {
			dphi += temp * temp;
		    }
		    c__ = w - dtisq * dpsi - dtipsq * dphi;
		}
		a = (dtipsq + dtisq) * w - dtipsq * dtisq * dw;
		b = dtipsq * dtisq * w;
		if (fabs(c__)<GMX_FLOAT_MIN) {
		    if (fabs(a)<GMX_FLOAT_MIN) {
			if (! swtch) {
			    if (orgati) {
				a = z__[*i__] * z__[*i__] + dtipsq * dtipsq * 
					(dpsi + dphi);
			    } else {
				a = z__[ip1] * z__[ip1] + dtisq * dtisq * (
					dpsi + dphi);
			    }
			} else {
			    a = dtisq * dtisq * dpsi + dtipsq * dtipsq * dphi;
			}
		    }
		    eta = b / a;
		} else if (a <= 0.) {
		  eta = (a - sqrt(fabs(a * a - b * 4. * c__))) / (c__ * 2.);
		} else {
		  eta = b * 2. / (a + sqrt(fabs(a * a - b * 4. * c__)));
		}
	    } else {

		dtiim = work[iim1] * delta[iim1];
		dtiip = work[iip1] * delta[iip1];
		temp = rhoinv + psi + phi;
		if (swtch) {
		    c__ = temp - dtiim * dpsi - dtiip * dphi;
		    zz[0] = dtiim * dtiim * dpsi;
		    zz[2] = dtiip * dtiip * dphi;
		} else {
		    if (orgati) {
			temp1 = z__[iim1] / dtiim;
			temp1 *= temp1;
			temp2 = (d__[iim1] - d__[iip1]) * (d__[iim1] + d__[
				iip1]) * temp1;
			c__ = temp - dtiip * (dpsi + dphi) - temp2;
			zz[0] = z__[iim1] * z__[iim1];
			if (dpsi < temp1) {
			    zz[2] = dtiip * dtiip * dphi;
			} else {
			    zz[2] = dtiip * dtiip * (dpsi - temp1 + dphi);
			}
		    } else {
			temp1 = z__[iip1] / dtiip;
			temp1 *= temp1;
			temp2 = (d__[iip1] - d__[iim1]) * (d__[iim1] + d__[
				iip1]) * temp1;
			c__ = temp - dtiim * (dpsi + dphi) - temp2;
			if (dphi < temp1) {
			    zz[0] = dtiim * dtiim * dpsi;
			} else {
			    zz[0] = dtiim * dtiim * (dpsi + (dphi - temp1));
			}
			zz[2] = z__[iip1] * z__[iip1];
		    }
		}
		dd[0] = dtiim;
		dd[1] = delta[ii] * work[ii];
		dd[2] = dtiip;
		F77_FUNC(slaed6,SLAED6)(&niter, &orgati, &c__, dd, zz, &w, &eta, info);
		if (*info != 0) {
		    goto L240;
		}
	    }

	    if (w * eta >= 0.) {
		eta = -w / dw;
	    }
	    if (orgati) {
		temp1 = work[*i__] * delta[*i__];
		temp = eta - temp1;
	    } else {
		temp1 = work[ip1] * delta[ip1];
		temp = eta - temp1;
	    }
	    if (temp > sg2ub || temp < sg2lb) {
		if (w < 0.) {
		    eta = (sg2ub - tau) / 2.;
		} else {
		    eta = (sg2lb - tau) / 2.;
		}
	    }

	    tau += eta;
	    eta /= *sigma + sqrt(*sigma * *sigma + eta);

	    *sigma += eta;
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
		work[j] += eta;
		delta[j] -= eta;
	    }

	    prew = w;

	    dpsi = 0.;
	    psi = 0.;
	    erretm = 0.;
	    i__1 = iim1;
	    for (j = 1; j <= i__1; ++j) {
		temp = z__[j] / (work[j] * delta[j]);
		psi += z__[j] * temp;
		dpsi += temp * temp;
		erretm += psi;
	    }
	    erretm = fabs(erretm);

	    dphi = 0.;
	    phi = 0.;
	    i__1 = iip1;
	    for (j = *n; j >= i__1; --j) {
		temp = z__[j] / (work[j] * delta[j]);
		phi += z__[j] * temp;
		dphi += temp * temp;
		erretm += phi;
	    }

	    temp = z__[ii] / (work[ii] * delta[ii]);
	    dw = dpsi + dphi + temp * temp;
	    temp = z__[ii] * temp;
	    w = rhoinv + phi + psi + temp;
	    erretm = (phi - psi) * 8. + erretm + rhoinv * 2. + fabs(temp) * 3. 
		    + fabs(tau) * dw;
	    if (w * prew > 0. && fabs(w) > fabs(prew) / 10.) {
		swtch = ! swtch;
	    }

	    if (w <= 0.) {
		sg2lb = (sg2lb > tau) ? sg2lb : tau;
	    } else {
		sg2ub = (sg2ub < tau) ? sg2ub : tau;
	    }
	}

	*info = 1;

    }

L240:
    return;

}