Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: New algorithm in the variation after projection calculations for
  non-yrast nuclear states   We present a novel and simple algorithm in the variation after projection
(VAP) approach for the non-yrast nuclear states. It is for the first time that
the yrast state and non-yrast states can be varied on the same footing. The
orthogonality among the calculated states is automatically fulfilled by solving
the Hill-Wheeler equation. This avoids the complexity of the frequently used
Gram-Schmidt orthogonalization, as adopted by the excited VAMPIR method. Thanks
to the Cauchy's interlacing theorem in the matrix theory, the sum of the
calculated lowest projected energies with the same quantum numbers can be
safely minimized. Once such minimization is converged, all the calculated
energies and the corresponding states can be obtained, simultaneously. The
present VAP calculations are performed with time-odd Hartree-Fock Slater
determinants. It is shown that the calculated VAP energies (both yrast and
non-yrast) are very close to the corresponding ones from the full shell model
calculations. It looks the present algorithm is not limited to the VAP, but
should be universal, i.e., one can do the variation with different forms of the
many-body wavefunctions to calculate the excited states in different quantum
many-body systems.

20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat