  Pulsation frequencies of acoustic modes are calculated for realistic rotating
stellar models using both a perturbative and a two-dimensional approach. A
comparison between the two yields validity domains which are similar to those
previously obtained in Reese, Lignieres and Rieutord (2006) for polytropic
models. One can also construct validity domains based on polynomial fits to the
frequencies from the two-dimensional approach, and these also turn out to be
similar, thus further confirming the agreement between the perturbative and
two-dimensional approach at low rotation rates. Furthermore, as was previously
shown in Espinosa, Perez Hernandez and Roca Cortes (2004), adjacent frequencies
in multiplets come close together, thus forming pairs. This phenomena,
exclusive to two-dimensional calculations, is shown to be an unlikely
explanation of the close frequency pairs observed in delta Scuti stars. A
systematic search for all close frequency pairs in the calculated spectrum is
also carried out. The number of close frequency pairs is shown to agree with
what is expected based on a Poisson distribution, but does not match the number
or distribution of close pairs in stars like FG Vir. Furthermore, a lack of
close frequency pairs appears at low rotation rates, where frequency multiplets
do not overlap. Delta Scuti stars currently reported as having close frequency
pairs do not fall in this interval.
