Dear Molpro developers,<br><br> My two CASSCF analytic hessian results (H2 and H3) are quite different from their corresponding numerical hessian ones. I used Molpro2012. The numerical hessian results are very similar to analytic hessian results by G09.<br>

<br>My input and key output files:<br>***,<br>memory,50,m;<br>basis=3-21G;<br>gprint,civector;<br>geomtyp=xyz<br>symmetry,noSym<br>geometry={<br>2<br><br> H          0.0000000000        0.0000000000        0.0061468834<br>

 H          0.0000000000        0.0000000000        0.7638536466<br>}<br>{casscf;occ,2;<br>wf,charge=0,symmetry=1,spin=0;<br>cpmcscf,hess<br>}<br>{frequencies,analytical<br>NOPROJECT<br>print,HESSIAN<br>}<br><br>----<br>
Analytical OUT (freq: 17056.95i & 3405.30):<br>
 Force Constants (Second Derivatives of the Energy) in [a.u.]<br>                             GX1         GY1         GZ1         GX2         GY2<br>           GX1           0.0000000<br>           GY1           0.0000000   0.0000000<br>

           GZ1           0.0000000   0.0000000   0.4272245<br>           GX2           0.0000000   0.0000000   0.0000000   0.0000000<br>           GY2           0.0000000   0.0000000   0.0000000   0.0000000   0.0000000<br>

           GZ2           0.0000000   0.0000000  -0.4171987   0.0000000   0.0000000<br>                             GZ2<br>           GZ2         -11.0826665<br><br>----<br>Numerical OUT (freq. 4265.22):<br> Force Constants (Second Derivatives of the Energy) in [a.u.]<br>

                             GX1         GY1         GZ1         GX2         GY2<br>           GX1           0.0483359<br>           GY1           0.0000000   0.0029962<br>           GZ1           0.0018526   0.0000000   0.0033110<br>

           GX2           0.0535733   0.0000000   0.0239807  -0.1071465<br>           GY2           0.0000000  -0.0123250   0.0000000   0.0000000   0.0246499<br>           GZ2          -0.0276819   0.0000000  -0.0216877   0.0000038   0.0000000<br>

           GX3          -0.1019092   0.0000000  -0.0258338   0.0535733   0.0000000<br>           GY3           0.0000000   0.0093287   0.0000000   0.0000000  -0.0123250<br>           GZ3           0.0258335   0.0000000   0.0183767  -0.0239705   0.0000000<br>

                             GZ2         GX3         GY3         GZ3<br>           GZ2           0.0433754<br>           GX3           0.0276845   0.0483359<br>           GY3           0.0000000   0.0000000   0.0029962<br>

           GZ3          -0.0216877  -0.0018486   0.0000000   0.0033110<br><br><br>---<br> ***,<br> memory,50,m;<br> basis=3-21G;<br> gprint,civector;<br> geomtyp=xyz<br> symmetry,noSym<br> geometry={<br> 3<br>  H         -0.0473124562        0.0000000000        0.0000000000<br>

  H          0.9000000000        0.0000000000        0.0000000000<br>  H          1.8473124562        0.0000000000        0.0000000000<br> }<br> {casscf;occ,3;<br> wf,charge=0,symmetry=1,spin=1;<br> cpmcscf,hess<br> }<br>

 {frequencies,analytical<br> NOPROJECT<br> print,HESSIAN<br> }<br><br>---<br>Analytical OUT (no imag. freq., but 4283.32):<br> Force Constants (Second Derivatives of the Energy) in [a.u.]<br>                             GX1         GY1         GZ1         GX2         GY2<br>

           GX1           0.3154326<br>           GY1           0.0000000   0.0055635<br>           GZ1           0.0000000   0.0000000   0.0055635<br>           GX2          -0.2332771   0.0000000   0.0000000   0.4665537<br>

           GY2           0.0000000  -0.0128431   0.0000000   0.0000000   0.0256862<br>           GZ2           0.0000000   0.0000000  -0.0128431   0.0000000   0.0000000<br>           GX3          -0.0821555   0.0000000   0.0000000  -0.2332769   0.0000000<br>

           GY3           0.0000000   0.0072796   0.0000000   0.0000000  -0.0128431<br>           GZ3           0.0000000   0.0000000   0.0072796   0.0000000   0.0000000<br>                             GZ2         GX3         GY3         GZ3<br>

           GZ2           0.0256862<br>           GX3           0.0000000   0.3154326<br>           GY3           0.0000000   0.0000000   0.0055635<br>           GZ3          -0.0128431   0.0000000   0.0000000   0.0055635<br>

<br>---<br>Numerical OUT (imag. freq. 2037.45):<br> Force Constants (Second Derivatives of the Energy) in [a.u.]<br>                             GX1         GY1         GZ1         GX2         GY2<br>           GX1           0.0484574<br>

           GY1           0.0000000   0.0055637<br>           GZ1           0.0000000   0.0000000   0.0055637<br>           GX2           0.0527820   0.0000000   0.0000000  -0.1055641<br>           GY2           0.0000000  -0.0128437   0.0000000   0.0000000   0.0256873<br>

           GZ2           0.0000000   0.0000000  -0.0128437   0.0000000   0.0000000<br>           GX3          -0.1012395   0.0000000   0.0000000   0.0527820   0.0000000<br>           GY3           0.0000000   0.0072800   0.0000000   0.0000000  -0.0128437<br>

           GZ3           0.0000000   0.0000000   0.0072800   0.0000000   0.0000000<br>                             GZ2         GX3         GY3         GZ3<br>           GZ2           0.0256873<br>           GX3           0.0000000   0.0484574<br>

           GY3           0.0000000   0.0000000   0.0055637<br>           GZ3          -0.0128437   0.0000000   0.0000000   0.0055637<br><br clear="all"><div>Best Wishes,<br><br>Oscar<br><br style="color:rgb(192,192,192)">

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