diff --git a/src/h5/h5_types.h b/src/h5/h5_types.h
index 9549b0c..1167e67 100644
--- a/src/h5/h5_types.h
+++ b/src/h5/h5_types.h
@@ -1,3 +1,4 @@
+
 #ifndef __H5_TYPES_H
 #define __H5_TYPES_H
 
@@ -17,16 +18,47 @@ typedef	h5_int64_t		h5_int_t;
 typedef	h5_int64_t		h5part_int64_t;
 typedef int32_t			h5_id_t;
 typedef int32_t			h5_size_t;	/* size in number of elements */
+typedef int32_t			h5_err_t;
 
 typedef double			h5_float64_t;
 typedef	h5_float64_t		h5_float_t;
 typedef	h5_float64_t		h5part_float64_t;
 
 struct h5_complex {
-	h5_float_t		r,i;
+	h5_float64_t		r,i;
 };
 typedef struct h5_complex	h5_complex;
 
+struct h5_vertex {  /* 32Byte */
+	h5_id_t		id;
+	h5_id_t		unused;	/* for right alignment */
+	h5_float64_t	P[3];
+};
+
+struct h5_edge { /* 16Bytes */
+	h5_id_t		id;
+	h5_id_t		parent_id;
+	h5_id_t		vertex_ids[2];
+};
+
+struct h5_triangle { /*24Bytes*/
+	h5_id_t		id;
+	h5_id_t		parent_id;
+	h5_id_t		vertex_ids[3];
+	h5_id_t		unused;	/* for alignment */
+};
+
+struct h5_tetrahedron { /* 24Bytes */
+	h5_id_t		id;
+	h5_id_t		parent_id;
+	h5_id_t		vertex_ids[4];
+};
+
+typedef struct h5_vertex	h5_vertex;
+typedef struct h5_edge		h5_edg;
+typedef struct h5_triangle	h5_triangle;
+typedef struct h5_tetrahedron	h5_tetrahedron;
+
 typedef h5_int64_t (*h5_error_handler)( const char*, const h5_int64_t, const char*,...)
 #ifdef __GNUC__
 __attribute__ ((format (printf, 3, 4)))
@@ -39,8 +71,9 @@ typedef h5_error_handler	h5part_error_handler;
 typedef unsigned long		MPI_Comm;
 #endif
 
-struct h5b_fdata;
-struct h5t_fdata;
+struct h5u_fdata;			/* unstructured data */ 
+struct h5b_fdata;			/* block structured data */
+struct h5t_fdata;			/* topology data */
 
 /**
    \struct h5_file
@@ -51,7 +84,38 @@ struct h5t_fdata;
    H5PartCloseFile().  
 */
 struct h5_file {
-	hsize_t nparticles;
+	hid_t	file;			/* file id -> fid		*/
+	int	empty;
+
+	unsigned mode;			/* file access mode		*/
+	hid_t	xfer_prop;
+	hid_t	create_prop;
+	hid_t	access_prop;
+
+	hid_t	root_gid;		/* id of group "/"		*/
+
+	int	nprocs;			/* number of processors		*/
+	int	myproc;			/* The index of the processor	
+					   this process is running on.	*/
+	MPI_Comm comm;			/* MPI communicator		*/
+
+	/* step internal data						*/
+	char	*prefix_step_name;	/* Prefix of step name		*/
+	int	width_step_idx;		/* pad step index with 0 up to this */
+
+	char	step_name[128];		/* full step name		*/
+	int	empty_step;
+       
+	h5_int64_t step_idx;		/* step index			*/
+	hid_t	step_gid;		/* HDF5 grp id of current step	*/
+
+
+	/*
+	  BEGIN unstructured stuff,
+	  should be moved to struct h5u_fdata
+	*/
+
+	hsize_t nparticles;		/* -> u.nparticles */
 	
 	h5part_int64_t viewstart; /* -1 if no view is available: A "view" looks */
 	h5part_int64_t viewend;   /* at a subset of the data. */
@@ -70,48 +134,66 @@ struct h5_file {
 	hid_t diskshape;
 	hid_t memshape;
 
-	/*
-	 */
-
-	hid_t	file;
-	unsigned mode;
-	hid_t xfer_prop;
-	hid_t create_prop;
-	hid_t access_prop;
-
-	hid_t	root_id;		/* id of group "/" */
-	char	*groupname_step;
-	int	stepno_width;
-	int	empty;
-
-	char	index_name[128];
-       
-	h5_int64_t timestep;
-	hid_t timegroup;
-
-
-	/**
-	   Number of processors
-	*/
-	int nprocs;
+	/* END unstructured */
 	
-	/**
-	   The index of the processor this process is running on.
-	*/
-	int myproc;
-
-	/**
-	   MPI comnunicator
-	*/
-	MPI_Comm comm;
-
+	struct h5u_fdata u;
 	struct h5b_fdata *block;
-	h5_int64_t (*close_block)(struct h5_file *f);
-
-	struct h5t_fdata *topo;
-	h5_int64_t (*close_topo)(struct h5_file *f);
+	struct h5t_fdata t;
 };
 
 typedef struct h5_file h5_file;
 
+struct h5u_fdata {
+	hsize_t nparticles;		/* -> u.nparticles */
+	
+	h5part_int64_t viewstart; /* -1 if no view is available: A "view" looks */
+	h5part_int64_t viewend;   /* at a subset of the data. */
+  
+	/**
+	   the number of particles in each processor.
+	   With respect to the "VIEW", these numbers
+	   can be regarded as non-overlapping subsections
+	   of the particle array stored in the file.
+	   So they can be used to compute the offset of
+	   the view for each processor
+	*/
+	h5part_int64_t *pnparticles;
+
+	hid_t shape;
+	hid_t diskshape;
+	hid_t memshape;
+}
+
+struct h5b_fdata {
+	h5part_int64_t step_idx;
+	h5part_int64_t i_max;
+	h5part_int64_t j_max;
+	h5part_int64_t k_max;
+	struct H5BlockPartition *user_layout;
+	struct H5BlockPartition *write_layout;
+	int have_layout;
+
+	hid_t shape;
+	hid_t memshape;
+	hid_t diskshape;
+	hid_t blockgroup;
+	hid_t field_group_id;
+};
+
+struct h5t_fdata_level {
+	int		new_level;
+	h5_id_t		last_stored_vertex; 
+	h5_size_t	num_vertices;
+	h5_vertex	* vertices;
+	h5_id_t		last_stored_tet;
+	h5_size_t	num_tets;
+	h5_tetrahedron	* tets;
+};
+
+struct h5t_fdata {
+	h5_id_t		cur_level;
+	h5_size_t	num_levels;
+	hid_t		mesh_gid;
+	struct h5t_fdata_level levels[];
+};
 #endif