  The detectors based on the liquid scintillator (LS) monitored by an array of
photo-multiplier tubes (PMT) are often used in low energy experiments such as
neutrino oscillation studies and search for dark matter. Detectors of this kind
operate in an energy range spanning from hundreds of keV to a few GeV providing
a few percent resolution at energies above 1 MeV and allowing to observe fine
spectral features. This article gives a brief overview of relevant physical
processes and introduces a new universal simulation tool LSMC (Liquid
Scintillator Monte Carlo) for simulation of LS-based detectors equipped with
PMT arrays. This tool is based on the Geant4 framework and provides
supplementing functionality for ease of configuration and comprehensive output.
The usage of LSMC is illustrated by modeling and optimization of a compact
detector prototype currently being built at Baksan Neutrino Observatory.
