@@ -76,25 +76,25 @@ possible determinants arising from this configuration,
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are components of one singlet and one triplet in the following combinations:
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- <img src =" ./figures/triplet-combinations.png " height =" 60 " >
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+ <img src =" ./figures/triplet-combinations.png " height =" 50 " >
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- <img src =" ./figures/singlet-combinations.png " height =" 60 " >
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+ <img src =" ./figures/singlet-combinations.png " height =" 50 " >
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where the superscript is the spin multiplicity (* 2S+1* ) and the subscript is
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the * M<sub >S</sub >* value of the wave function. So, if we wanted to compute
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only the eigenvalues and eigenfunctions corresponding spin singlets in our CIS
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- calculation, we could introduce the restriction on our CIS coefficients that
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- < html > & alpha ; </ html > and <html >&beta ; </html > excitations involving the same
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- * spatial * orbitals must be identical (including the sign). Similarly, if we
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- wanted only triplets, we could require that the <html >&alpha ; </html > and
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- < html > & beta ; </ html > excitations have the same magnitude but opposite signs.
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+ calculation, we could introduce the restriction on our CIS coefficients that < html > & alpha ; </ html >
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+ and <html >&beta ; </html > excitations involving the same < i >spatial</ i > orbitals
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+ must be identical (including the sign). Similarly, if we wanted only triplets,
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+ we could require that the <html >&alpha ; </html > and < html > & beta ; </ html > excitations
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+ have the same magnitude but opposite signs.
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Let's begin with the singlets. Starting from the spin-orbital eigenvalue
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expression and the equation for the CIS Hamiltonian matrix elements in the
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previous section, we may write a spin-factored equation for the <html >&alpha ; </html >
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coefficients as
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- <img src =" ./figures/spin-factored-eqn.png " height =" 60 " >
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+ <img src =" ./figures/spin-factored-eqn.png " height =" 55 " >
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Note that the mix-spin cases (where * j=* <html >&alpha ; </html > and
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* b=* <html >&beta ; </html > or * vice versa* ) do not contribute since the Fock
@@ -176,19 +176,19 @@ Hamiltonian storage cost), one can rearrange the eigenvalue equations. First
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write eigenvalue equation two separate equations, each in terms of the
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submatrices ** A** and ** B** :
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- <img src =" ./figures/smarter-tdhf-1.png " height =" 25 " >
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+ <img src =" ./figures/smarter-tdhf-1.png " height =" 22.5 " >
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and
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- <img src =" ./figures/smarter-tdhf-2.png " height =" 25 " >
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+ <img src =" ./figures/smarter-tdhf-2.png " height =" 22.5 " >
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Now take +/- combinations of these equations to obtain
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- <img src =" ./figures/smarter-tdhf-3.png " height =" 25 " >
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+ <img src =" ./figures/smarter-tdhf-3.png " height =" 22.5 " >
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and
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- <img src =" ./figures/smarter-tdhf-4.png " height =" 25 " >
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+ <img src =" ./figures/smarter-tdhf-4.png " height =" 22.5 " >
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Solve for *** (X+Y)*** in the second equation:
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