Context : In the framework of the Virtual Observatory ( VO ) , the German Astrophysical Virtual Observatory ( GAVO ) developed the registered service TheoSSA ( Theoretical Stellar Spectra Access ) .
It provides easy access to stellar spectral energy distributions ( SEDs ) and is intended to ingest SEDs calculated by any model-atmosphere code , generally for all effective temperature , surface gravities , and elemental compositions .
We will establish a database of SEDs of flux standards that are easily accessible via TheoSSA ’ s web interface .

Aims : The OB-type subdwarf Feige 110 is a standard star for flux calibration .
State-of-the-art non-local thermodynamic equilibrium ( NLTE ) stellar-atmosphere models that consider opacities of species up to trans-iron elements will be used to provide a reliable synthetic spectrum to compare with observations .

Methods : In case of Feige 110 , we demonstrate that the model reproduces not only its overall continuum shape from the far-ultraviolet ( FUV ) to the optical wavelength range but also the numerous metal lines exhibited in its FUV spectrum .

Results : We present a state-of-the-art spectral analysis of Feige 110 .
We determined \mbox { $T _ { \mathrm { eff } } $ } \hskip { -1.422638 pt } = \hskip { -1.422638 pt } 47 250 \pm 200 % 0 \mathrm { K } , \log g \hskip { -1.422638 pt } = \hskip { -1.422638 pt } 6.00 \pm 0.20 , and the abundances of He , N , P , S , Ti , V , Cr , Mn , Fe , Co , Ni , Zn , and Ge .
Ti , V , Mn , Co , Zn , and Ge were identified for the first time in this star .
Upper abundance limits were derived for C , O , Si , Ca , and Sc .

Conclusions : The TheoSSA database of theoretical SEDs of stellar flux standards guarantees that the flux calibration of astronomical data and cross-calibration between different instruments can be based on models and SEDs calculated with state-of-the-art model-atmosphere codes .