Hey @oyardas2. On one of your lattices, you have a <lower_left> that includes the value 1.08221785365e-312. The problem is that IEEE-754 doubles have a range of about [2e-308, 1.8e308], meaning that particular value is too small to be represented using a double (hence the std::out_of_range exception getting thrown when that value is passed to std::stod).