res = new Topo_Cart(getComm(), newNDims, newDims, newPeriodic, 0, newcomm);
} else {
*newcomm = getComm()->split(color, getComm()->rank());
res = new Topo_Cart(getComm(), newNDims, newDims, newPeriodic, 0, newcomm);
} else {
*newcomm = getComm()->split(color, getComm()->rank());