For scientific computing, whether a language has very advanced or merely okay functional features is only a superficial style issue.
Regarding more important performance issues like low level control of memory layout and avoiding pointless copying and indirection, C++ and Fortran are both at the most effective end of the spectrum, while typical functional languages lie between "don't even think about it, by design" and "it might be OK but only a fool would put a project at the mercy of what optimizations a relatively unproven compiler opts to do".
Regarding more important performance issues like low level control of memory layout and avoiding pointless copying and indirection, C++ and Fortran are both at the most effective end of the spectrum, while typical functional languages lie between "don't even think about it, by design" and "it might be OK but only a fool would put a project at the mercy of what optimizations a relatively unproven compiler opts to do".