  We investigate the mass spectrum of 1^{+} exotic mesons with quark content
(\c\s\cbar\qbar) or (\c\q\cbar\sbar), using molecular and diquark-antidiquark
operators, in quenched lattice QCD with exact chiral symmetry. For the
molecular operator
{(\qbar\gamma_i\c)(\cbar\gamma_5\s)-(\cbar\gamma_i\s)(\qbar\gamma_5\c)} and the
diquark-antidiquark operator {(\q^T C \gamma_i \c)(\sbar C \gamma_5 \cbar^T)-
(\q^T C \gamma_5 \c)(\sbar C \gamma_i^T \cbar^T)}, both detect a 1^{+}
resonance with mass around 4010 +- 50 MeV in the limit m_q -> m_{u,d}.
