diff --git a/scripts/utility/decorator.py b/scripts/utility/decorator.py
new file mode 100644
index 00000000..66b9e064
--- /dev/null
+++ b/scripts/utility/decorator.py
@@ -0,0 +1,26 @@
+from functools import wraps
+
+def cache(func):
+    """
+    A decorator for lazy evaluation off true function
+    """
+    saved = {}
+
+    @wraps(func)
+    def newfunc(*args):
+        if args in saved:
+            return saved[args]
+
+        result = func(*args)
+        saved[args] = result
+        return result
+    return newfunc
+
+
+class classproperty(object):
+
+    def __init__(self, fget):
+        self.fget = fget
+
+    def __get__(self, owner_self, owner_cls):
+        return self.fget(owner_cls)
diff --git a/src/CAS_SD/Makefile b/src/CAS_SD/Makefile
deleted file mode 100644
index bfcd2493..00000000
--- a/src/CAS_SD/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-IRPF90 = irpf90  #-a -d
-FC     = gfortran
-FCFLAGS= -O2 -ffree-line-length-none -I .
-NINJA  = ninja
-AR     = ar
-RANLIB = ranlib
-
-SRC=
-OBJ=
-LIB=
-
-include irpf90.make
-export
-
-irpf90.make: $(filter-out IRPF90_temp/%, $(wildcard */*.irp.f)) $(wildcard *.irp.f) $(wildcard *.inc.f) Makefile 
-	$(IRPF90)
diff --git a/src/CID/Makefile b/src/CID/Makefile
deleted file mode 100644
index bfcd2493..00000000
--- a/src/CID/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-IRPF90 = irpf90  #-a -d
-FC     = gfortran
-FCFLAGS= -O2 -ffree-line-length-none -I .
-NINJA  = ninja
-AR     = ar
-RANLIB = ranlib
-
-SRC=
-OBJ=
-LIB=
-
-include irpf90.make
-export
-
-irpf90.make: $(filter-out IRPF90_temp/%, $(wildcard */*.irp.f)) $(wildcard *.irp.f) $(wildcard *.inc.f) Makefile 
-	$(IRPF90)
diff --git a/src/CID_SC2_selected/Makefile b/src/CID_SC2_selected/Makefile
deleted file mode 100644
index bfcd2493..00000000
--- a/src/CID_SC2_selected/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-IRPF90 = irpf90  #-a -d
-FC     = gfortran
-FCFLAGS= -O2 -ffree-line-length-none -I .
-NINJA  = ninja
-AR     = ar
-RANLIB = ranlib
-
-SRC=
-OBJ=
-LIB=
-
-include irpf90.make
-export
-
-irpf90.make: $(filter-out IRPF90_temp/%, $(wildcard */*.irp.f)) $(wildcard *.irp.f) $(wildcard *.inc.f) Makefile 
-	$(IRPF90)
diff --git a/src/CID_selected/Makefile b/src/CID_selected/Makefile
deleted file mode 100644
index bfcd2493..00000000
--- a/src/CID_selected/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-IRPF90 = irpf90  #-a -d
-FC     = gfortran
-FCFLAGS= -O2 -ffree-line-length-none -I .
-NINJA  = ninja
-AR     = ar
-RANLIB = ranlib
-
-SRC=
-OBJ=
-LIB=
-
-include irpf90.make
-export
-
-irpf90.make: $(filter-out IRPF90_temp/%, $(wildcard */*.irp.f)) $(wildcard *.irp.f) $(wildcard *.inc.f) Makefile 
-	$(IRPF90)
diff --git a/src/CIS/Makefile b/src/CIS/Makefile
deleted file mode 100644
index bfcd2493..00000000
--- a/src/CIS/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-IRPF90 = irpf90  #-a -d
-FC     = gfortran
-FCFLAGS= -O2 -ffree-line-length-none -I .
-NINJA  = ninja
-AR     = ar
-RANLIB = ranlib
-
-SRC=
-OBJ=
-LIB=
-
-include irpf90.make
-export
-
-irpf90.make: $(filter-out IRPF90_temp/%, $(wildcard */*.irp.f)) $(wildcard *.irp.f) $(wildcard *.inc.f) Makefile 
-	$(IRPF90)
diff --git a/src/CISD/Makefile b/src/CISD/Makefile
deleted file mode 100644
index bfcd2493..00000000
--- a/src/CISD/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-IRPF90 = irpf90  #-a -d
-FC     = gfortran
-FCFLAGS= -O2 -ffree-line-length-none -I .
-NINJA  = ninja
-AR     = ar
-RANLIB = ranlib
-
-SRC=
-OBJ=
-LIB=
-
-include irpf90.make
-export
-
-irpf90.make: $(filter-out IRPF90_temp/%, $(wildcard */*.irp.f)) $(wildcard *.irp.f) $(wildcard *.inc.f) Makefile 
-	$(IRPF90)
diff --git a/src/CISD_SC2_selected/Makefile b/src/CISD_SC2_selected/Makefile
deleted file mode 100644
index bfcd2493..00000000
--- a/src/CISD_SC2_selected/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-IRPF90 = irpf90  #-a -d
-FC     = gfortran
-FCFLAGS= -O2 -ffree-line-length-none -I .
-NINJA  = ninja
-AR     = ar
-RANLIB = ranlib
-
-SRC=
-OBJ=
-LIB=
-
-include irpf90.make
-export
-
-irpf90.make: $(filter-out IRPF90_temp/%, $(wildcard */*.irp.f)) $(wildcard *.irp.f) $(wildcard *.inc.f) Makefile 
-	$(IRPF90)
diff --git a/src/CISD_selected/Makefile b/src/CISD_selected/Makefile
deleted file mode 100644
index bfcd2493..00000000
--- a/src/CISD_selected/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-IRPF90 = irpf90  #-a -d
-FC     = gfortran
-FCFLAGS= -O2 -ffree-line-length-none -I .
-NINJA  = ninja
-AR     = ar
-RANLIB = ranlib
-
-SRC=
-OBJ=
-LIB=
-
-include irpf90.make
-export
-
-irpf90.make: $(filter-out IRPF90_temp/%, $(wildcard */*.irp.f)) $(wildcard *.irp.f) $(wildcard *.inc.f) Makefile 
-	$(IRPF90)
diff --git a/src/DDCI_selected/Makefile b/src/DDCI_selected/Makefile
deleted file mode 100644
index bfcd2493..00000000
--- a/src/DDCI_selected/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-IRPF90 = irpf90  #-a -d
-FC     = gfortran
-FCFLAGS= -O2 -ffree-line-length-none -I .
-NINJA  = ninja
-AR     = ar
-RANLIB = ranlib
-
-SRC=
-OBJ=
-LIB=
-
-include irpf90.make
-export
-
-irpf90.make: $(filter-out IRPF90_temp/%, $(wildcard */*.irp.f)) $(wildcard *.irp.f) $(wildcard *.inc.f) Makefile 
-	$(IRPF90)
diff --git a/src/DensityFit/.gitignore b/src/DensityFit/.gitignore
new file mode 100644
index 00000000..7ac9fbf6
--- /dev/null
+++ b/src/DensityFit/.gitignore
@@ -0,0 +1,5 @@
+IRPF90_temp/
+IRPF90_man/
+irpf90.make
+irpf90_entities
+tags
\ No newline at end of file
diff --git a/src/Determinants/Makefile b/src/Determinants/Makefile
deleted file mode 100644
index bfcd2493..00000000
--- a/src/Determinants/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-IRPF90 = irpf90  #-a -d
-FC     = gfortran
-FCFLAGS= -O2 -ffree-line-length-none -I .
-NINJA  = ninja
-AR     = ar
-RANLIB = ranlib
-
-SRC=
-OBJ=
-LIB=
-
-include irpf90.make
-export
-
-irpf90.make: $(filter-out IRPF90_temp/%, $(wildcard */*.irp.f)) $(wildcard *.irp.f) $(wildcard *.inc.f) Makefile 
-	$(IRPF90)
diff --git a/src/FCIdump/Makefile b/src/FCIdump/Makefile
deleted file mode 100644
index bfcd2493..00000000
--- a/src/FCIdump/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-IRPF90 = irpf90  #-a -d
-FC     = gfortran
-FCFLAGS= -O2 -ffree-line-length-none -I .
-NINJA  = ninja
-AR     = ar
-RANLIB = ranlib
-
-SRC=
-OBJ=
-LIB=
-
-include irpf90.make
-export
-
-irpf90.make: $(filter-out IRPF90_temp/%, $(wildcard */*.irp.f)) $(wildcard *.irp.f) $(wildcard *.inc.f) Makefile 
-	$(IRPF90)
diff --git a/src/Full_CI/Makefile b/src/Full_CI/Makefile
deleted file mode 100644
index bfcd2493..00000000
--- a/src/Full_CI/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-IRPF90 = irpf90  #-a -d
-FC     = gfortran
-FCFLAGS= -O2 -ffree-line-length-none -I .
-NINJA  = ninja
-AR     = ar
-RANLIB = ranlib
-
-SRC=
-OBJ=
-LIB=
-
-include irpf90.make
-export
-
-irpf90.make: $(filter-out IRPF90_temp/%, $(wildcard */*.irp.f)) $(wildcard *.irp.f) $(wildcard *.inc.f) Makefile 
-	$(IRPF90)
diff --git a/src/Hartree_Fock/Makefile b/src/Hartree_Fock/Makefile
deleted file mode 100644
index bfcd2493..00000000
--- a/src/Hartree_Fock/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-IRPF90 = irpf90  #-a -d
-FC     = gfortran
-FCFLAGS= -O2 -ffree-line-length-none -I .
-NINJA  = ninja
-AR     = ar
-RANLIB = ranlib
-
-SRC=
-OBJ=
-LIB=
-
-include irpf90.make
-export
-
-irpf90.make: $(filter-out IRPF90_temp/%, $(wildcard */*.irp.f)) $(wildcard *.irp.f) $(wildcard *.inc.f) Makefile 
-	$(IRPF90)
diff --git a/src/Integrals_Monoelec/Makefile b/src/Integrals_Monoelec/Makefile
deleted file mode 100644
index bfcd2493..00000000
--- a/src/Integrals_Monoelec/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-IRPF90 = irpf90  #-a -d
-FC     = gfortran
-FCFLAGS= -O2 -ffree-line-length-none -I .
-NINJA  = ninja
-AR     = ar
-RANLIB = ranlib
-
-SRC=
-OBJ=
-LIB=
-
-include irpf90.make
-export
-
-irpf90.make: $(filter-out IRPF90_temp/%, $(wildcard */*.irp.f)) $(wildcard *.irp.f) $(wildcard *.inc.f) Makefile 
-	$(IRPF90)
diff --git a/src/MOGuess/Makefile b/src/MOGuess/Makefile
deleted file mode 100644
index bfcd2493..00000000
--- a/src/MOGuess/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-IRPF90 = irpf90  #-a -d
-FC     = gfortran
-FCFLAGS= -O2 -ffree-line-length-none -I .
-NINJA  = ninja
-AR     = ar
-RANLIB = ranlib
-
-SRC=
-OBJ=
-LIB=
-
-include irpf90.make
-export
-
-irpf90.make: $(filter-out IRPF90_temp/%, $(wildcard */*.irp.f)) $(wildcard *.irp.f) $(wildcard *.inc.f) Makefile 
-	$(IRPF90)
diff --git a/src/MP2/Makefile b/src/MP2/Makefile
deleted file mode 100644
index bfcd2493..00000000
--- a/src/MP2/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-IRPF90 = irpf90  #-a -d
-FC     = gfortran
-FCFLAGS= -O2 -ffree-line-length-none -I .
-NINJA  = ninja
-AR     = ar
-RANLIB = ranlib
-
-SRC=
-OBJ=
-LIB=
-
-include irpf90.make
-export
-
-irpf90.make: $(filter-out IRPF90_temp/%, $(wildcard */*.irp.f)) $(wildcard *.irp.f) $(wildcard *.inc.f) Makefile 
-	$(IRPF90)
diff --git a/src/MRCC/Makefile b/src/MRCC/Makefile
deleted file mode 100644
index bfcd2493..00000000
--- a/src/MRCC/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-IRPF90 = irpf90  #-a -d
-FC     = gfortran
-FCFLAGS= -O2 -ffree-line-length-none -I .
-NINJA  = ninja
-AR     = ar
-RANLIB = ranlib
-
-SRC=
-OBJ=
-LIB=
-
-include irpf90.make
-export
-
-irpf90.make: $(filter-out IRPF90_temp/%, $(wildcard */*.irp.f)) $(wildcard *.irp.f) $(wildcard *.inc.f) Makefile 
-	$(IRPF90)
diff --git a/src/Molden/Makefile b/src/Molden/Makefile
deleted file mode 100644
index bfcd2493..00000000
--- a/src/Molden/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-IRPF90 = irpf90  #-a -d
-FC     = gfortran
-FCFLAGS= -O2 -ffree-line-length-none -I .
-NINJA  = ninja
-AR     = ar
-RANLIB = ranlib
-
-SRC=
-OBJ=
-LIB=
-
-include irpf90.make
-export
-
-irpf90.make: $(filter-out IRPF90_temp/%, $(wildcard */*.irp.f)) $(wildcard *.irp.f) $(wildcard *.inc.f) Makefile 
-	$(IRPF90)
diff --git a/src/QmcChem/Makefile b/src/QmcChem/Makefile
deleted file mode 100644
index bfcd2493..00000000
--- a/src/QmcChem/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-IRPF90 = irpf90  #-a -d
-FC     = gfortran
-FCFLAGS= -O2 -ffree-line-length-none -I .
-NINJA  = ninja
-AR     = ar
-RANLIB = ranlib
-
-SRC=
-OBJ=
-LIB=
-
-include irpf90.make
-export
-
-irpf90.make: $(filter-out IRPF90_temp/%, $(wildcard */*.irp.f)) $(wildcard *.irp.f) $(wildcard *.inc.f) Makefile 
-	$(IRPF90)
diff --git a/src/Utils/constants.include.F b/src/Utils/constants.include.F
new file mode 100644
index 00000000..632dc50b
--- /dev/null
+++ b/src/Utils/constants.include.F
@@ -0,0 +1,10 @@
+integer, parameter :: max_dim = 255
+integer, parameter :: SIMD_vector = 32
+
+double precision, parameter :: pi =  dacos(-1.d0)
+double precision, parameter :: sqpi =  dsqrt(dacos(-1.d0))
+double precision, parameter :: pi_5_2 =  34.9868366552d0
+double precision, parameter :: dfour_pi =  4.d0*dacos(-1.d0)
+double precision, parameter :: dtwo_pi =  2.d0*dacos(-1.d0)
+double precision, parameter :: inv_sq_pi =  1.d0/dsqrt(dacos(-1.d0))
+double precision, parameter :: inv_sq_pi_2 = 0.5d0/dsqrt(dacos(-1.d0))