diff --git a/fortran/trimspNL.F b/fortran/trimspNL.F
index f6fb1ab..7c8184c 100644
--- a/fortran/trimspNL.F
+++ b/fortran/trimspNL.F
@@ -289,7 +289,8 @@ C     CHARACTER Variables
       CHARACTER month_start*4,month_stop*4,day_start*2,day_stop*2
       CHARACTER year_start*4,year_stop*4,hour_start*2,hour_stop*2
       CHARACTER min_start*2,min_stop*2,sec_start*2,sec_stop*2
-
+      CHARACTER*18 chem(MAXNL)
+      
       COMMON    /A/ M1,VELC,ZARG
       COMMON    /B/ TI,SHEATH,CALFA
 
@@ -409,8 +410,8 @@ C     Third line: Number of layers
 C     Here we read the NLayers structure
          DO I=1,NLayers
 C     Thickness (DX), density (RHO), and correction factor (CK, it is
-C     always 1.0??)
-            READ(11,*) DX(I),RHO(I),CK(I)
+C     always 1.0??), chemical formula (chem)
+            READ(11,*) DX(I),RHO(I),CK(I),chem(I)
 C     Atomic numbers
             READ(11,*) ZT(I,1),ZT(I,2),ZT(I,3),ZT(I,4),ZT(I,5)
 C     Mass numbers (amu)
@@ -3432,7 +3433,9 @@ c
       inquire(FILE='fort.33',EXIST=FORT33)
       if (.not.FORT33) then
          open(33)
-         WRITE(33,7802)  ('impL',k,k=1,NLayers)
+C     This is where we can insert the chemical formula         
+C     WRITE(33,7802)  ('impL',k,k=1,NLayers)
+         WRITE(33,7802)  (chem(k),k=1,NLayers)
       else
          open(33,access='append')
       endif