  Dynamical mean-field theory (DMFT) is one of the most widely-used methods to
treat accurately electron correlation effects in ab-initio real material
calculations. Many modern large-scale implementations of DMFT in electronic
structure codes involve solving a quantum impurity model with a Continuous-Time
Quantum Monte Carlo (CT-QMC) solver. The main advantage of CT-QMC is that,
unlike standard quantum Monte Carlo approaches, it is able to generate the
local Green's functions of the correlated system on an arbitrarily fine
imaginary time grid, and is free of any systematic errors. In this work, we
extend a hybrid QMC solver proposed by Khatami et al. and Rost et al. to a
multi-orbital context. This has the advantage of enabling impurity solver QMC
calculations to scale linearly with inverse temperature and permit its
application to d and f band materials. In addition, we present a novel Green's
function processing scheme which generates accurate quasi-continuous imaginary
time solutions of the impurity problem which overcome errors inherent to
standard QMC approaches. This solver and processing scheme are incorporated
into a full DFT+DMFT calculation using the CASTEP DFT code. Benchmark
calculations for strontium vanadate properties are presented.
