We analyze breaking of symmetries that belong to the double point
group D
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(three mutually perpendicular symmetry axes of the
second order, inversion, and time reversal). Subgroup structure of
the D
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group indicates that there can be as much as 28 physically
different, broken-symmetry mean-field schemes -- starting with
solutions obeying all the symmetries of the D
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group, through 26
generic schemes in which only a non-trivial subgroup of D
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is
conserved, down to solutions that break all of the D
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symmetries. Choices of single-particle bases and the corresponding
structures of single-particle hermitian operators are discussed for
several subgroups of D
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.