Index: tests/regression/Parser/Tremolo-SetAtomdata/post/output.data
===================================================================
--- tests/regression/Parser/Tremolo-SetAtomdata/post/output.data	(revision ca331ceac7b5334d5556ab0315bbb33b93f58f63)
+++ tests/regression/Parser/Tremolo-SetAtomdata/post/output.data	(revision ca331ceac7b5334d5556ab0315bbb33b93f58f63)
@@ -0,0 +1,4 @@
+# ATOMDATA	Id	type	x=3
+# Box	20	0	0	0	20	0	0	0	20
+1	Ar	4.72977	8	8	
+2	Ar	7.3	8	8	
Index: tests/regression/Parser/Tremolo-SetAtomdata/post/undo.data
===================================================================
--- tests/regression/Parser/Tremolo-SetAtomdata/post/undo.data	(revision ca331ceac7b5334d5556ab0315bbb33b93f58f63)
+++ tests/regression/Parser/Tremolo-SetAtomdata/post/undo.data	(revision ca331ceac7b5334d5556ab0315bbb33b93f58f63)
@@ -0,0 +1,4 @@
+# ATOMDATA	Id	name	type	x=3
+# Box	20	0	0	0	20	0	0	0	20
+1	Ar1	Ar	4.72977	8	8	
+2	Ar2	Ar	7.3	8	8	
Index: tests/regression/Parser/Tremolo-SetAtomdata/testsuite-parser-tremolo-resetatomdata.at
===================================================================
--- tests/regression/Parser/Tremolo-SetAtomdata/testsuite-parser-tremolo-resetatomdata.at	(revision ca331ceac7b5334d5556ab0315bbb33b93f58f63)
+++ tests/regression/Parser/Tremolo-SetAtomdata/testsuite-parser-tremolo-resetatomdata.at	(revision ca331ceac7b5334d5556ab0315bbb33b93f58f63)
@@ -0,0 +1,34 @@
+### parsing tremolo
+
+AT_SETUP([Parser - set tremolo's atomdata])
+AT_KEYWORDS([parser tremolo set-tremolo-atomdata])
+
+file=argon.data
+AT_CHECK([/bin/cp ${abs_top_srcdir}/tests/regression/Parser/Tremolo-SetAtomdata/pre/argon.data $file], 0, [ignore], [ignore])
+AT_CHECK([chmod u+w $file], 0, [ignore], [ignore])
+AT_CHECK([../../molecuilder -i argon.data --set-tremolo-atomdata "Id type x=3" --reset 1], 0, [stdout], [ignore])
+AT_CHECK([diff -I '%.*' $file ${abs_top_srcdir}/tests/regression/Parser/Tremolo-SetAtomdata/post/output.data], 0, [ignore], [ignore])
+
+AT_CLEANUP
+
+AT_SETUP([Parser - set tremolo's atomdata with Undo])
+AT_KEYWORDS([parser tremolo set-tremolo-atomdata undo])
+
+file=argon.data
+AT_CHECK([/bin/cp ${abs_top_srcdir}/tests/regression/Parser/Tremolo-SetAtomdata/pre/argon.data $file], 0, [ignore], [ignore])
+AT_CHECK([chmod u+w $file], 0, [ignore], [ignore])
+AT_CHECK([../../molecuilder -i argon.data --set-tremolo-atomdata "Id type x=3" --reset 1 --undo], 0, [stdout], [ignore])
+AT_CHECK([diff -I '%.*' $file ${abs_top_srcdir}/tests/regression/Parser/Tremolo-SetAtomdata/post/undo.data], 0, [ignore], [ignore])
+
+AT_CLEANUP
+
+AT_SETUP([Parser - set tremolo's atomdata with Redo])
+AT_KEYWORDS([parser tremolo set-tremolo-atomdata redo])
+
+file=argon.data
+AT_CHECK([/bin/cp ${abs_top_srcdir}/tests/regression/Parser/Tremolo-SetAtomdata/pre/argon.data $file], 0, [ignore], [ignore])
+AT_CHECK([chmod u+w $file], 0, [ignore], [ignore])
+AT_CHECK([../../molecuilder -i argon.data --set-tremolo-atomdata "Id type x=3" --reset 1 --undo --redo], 0, [stdout], [ignore])
+AT_CHECK([diff -I '%.*' $file ${abs_top_srcdir}/tests/regression/Parser/Tremolo-SetAtomdata/post/output.data], 0, [ignore], [ignore])
+
+AT_CLEANUP
Index: tests/regression/Parser/Tremolo-SetAtomdata/testsuite-parser-tremolo-setatomdata.at
===================================================================
--- tests/regression/Parser/Tremolo-SetAtomdata/testsuite-parser-tremolo-setatomdata.at	(revision 5b0581944c6a32b73762473862229922ce1b40eb)
+++ tests/regression/Parser/Tremolo-SetAtomdata/testsuite-parser-tremolo-setatomdata.at	(revision ca331ceac7b5334d5556ab0315bbb33b93f58f63)
@@ -1,5 +1,5 @@
 ### parsing tremolo
 
-AT_SETUP([Parser - set tremolo's atomdata])
+AT_SETUP([Parser - reset tremolo's atomdata])
 AT_KEYWORDS([parser tremolo set-tremolo-atomdata])
 
@@ -8,5 +8,27 @@
 AT_CHECK([chmod u+w $file], 0, [ignore], [ignore])
 AT_CHECK([../../molecuilder -i argon.data --set-tremolo-atomdata "type x=3"], 0, [stdout], [ignore])
-AT_CHECK([file=argon.data; diff -I '%.*' $file ${abs_top_srcdir}/tests/regression/Parser/Tremolo-SetAtomdata/post/argon.data], 0, [ignore], [ignore])
+AT_CHECK([diff -I '%.*' $file ${abs_top_srcdir}/tests/regression/Parser/Tremolo-SetAtomdata/post/argon.data], 0, [ignore], [ignore])
 
 AT_CLEANUP
+
+AT_SETUP([Parser - reset tremolo's atomdata with Undo])
+AT_KEYWORDS([parser tremolo set-tremolo-atomdata undo])
+
+file=argon.data
+AT_CHECK([/bin/cp ${abs_top_srcdir}/tests/regression/Parser/Tremolo-SetAtomdata/pre/argon.data $file], 0, [ignore], [ignore])
+AT_CHECK([chmod u+w $file], 0, [ignore], [ignore])
+AT_CHECK([../../molecuilder -i argon.data --set-tremolo-atomdata "type x=3" --undo], 0, [stdout], [ignore])
+AT_CHECK([diff -I '%.*' $file ${abs_top_srcdir}/tests/regression/Parser/Tremolo-SetAtomdata/post/undo.data], 0, [ignore], [ignore])
+
+AT_CLEANUP
+
+AT_SETUP([Parser - reset tremolo's atomdata with Redo])
+AT_KEYWORDS([parser tremolo set-tremolo-atomdata redo])
+
+file=argon.data
+AT_CHECK([/bin/cp ${abs_top_srcdir}/tests/regression/Parser/Tremolo-SetAtomdata/pre/argon.data $file], 0, [ignore], [ignore])
+AT_CHECK([chmod u+w $file], 0, [ignore], [ignore])
+AT_CHECK([../../molecuilder -i argon.data --set-tremolo-atomdata "type x=3" --undo --redo], 0, [stdout], [ignore])
+AT_CHECK([diff -I '%.*' $file ${abs_top_srcdir}/tests/regression/Parser/Tremolo-SetAtomdata/post/argon.data], 0, [ignore], [ignore])
+
+AT_CLEANUP
Index: tests/regression/Parser/Tremolo/post/water-neighbors.data
===================================================================
--- tests/regression/Parser/Tremolo/post/water-neighbors.data	(revision ca331ceac7b5334d5556ab0315bbb33b93f58f63)
+++ tests/regression/Parser/Tremolo/post/water-neighbors.data	(revision ca331ceac7b5334d5556ab0315bbb33b93f58f63)
@@ -0,0 +1,4 @@
+# ATOMDATA Id name resName resSeq x=3 charge type neighbors=2
+  1  OH2 TIP3  1   1.583   1.785   1.480 -0.8340  O    2   3
+  2  H1  TIP3  1   1.186   1.643   2.213  0.4170  H    1   0
+  3  H2  TIP3  1   2.642   1.896   1.730  0.4170  H    1   0
Index: tests/regression/Parser/testsuite-parser.at
===================================================================
--- tests/regression/Parser/testsuite-parser.at	(revision 5b0581944c6a32b73762473862229922ce1b40eb)
+++ tests/regression/Parser/testsuite-parser.at	(revision ca331ceac7b5334d5556ab0315bbb33b93f58f63)
@@ -59,4 +59,5 @@
 # setting tremolo's atomdata line
 m4_include([Parser/Tremolo-SetAtomdata/testsuite-parser-tremolo-setatomdata.at])
+m4_include([Parser/Tremolo-SetAtomdata/testsuite-parser-tremolo-resetatomdata.at])
 
 # writing and exttypes file
