update Gvec class
update Gvec class

electronic-structure/sirius,electronic-structure/sirius,toxa81/sirius,toxa81/sirius,toxa81/sirius,electronic-structure/sirius,electronic-structure/sirius,toxa81/sirius,electronic-structure/sirius,electronic-structure/sirius,electronic-structure/sirius,toxa81/sirius,toxa81/sirius