Merge pull request #649 from bobmyhill/merge_bm

merge BM EoSes and rename BM2 as BM3Shear2

Author: bobmyhill

burnman/calibrants/Decker_1971.py

@@ -9,25 +9,25 @@
 """
 
 from burnman.eos.mie_grueneisen_debye import MGDBase
+from burnman.eos.birch_murnaghan import pressure_fourth_order
 from burnman.classes.calibrant import Calibrant
-from burnman.eos.birch_murnaghan_4th import pressure_birch_murnaghan_fourth
 
 
 class NaCl_B1(Calibrant):
     """
     The NaCl (B1 structured) pressure standard reported by
     Decker (1971; https://doi.org/10.1063/1.1660714).
 
-    .. note:: This calibrant is not exactly the same as that proposed by Decker.
-        The cold compression curve has here been approximated by a 4th order
-        Birch-Murnaghan EoS, as described in
+    .. note:: This calibrant is not exactly the same as that
+        proposed by Decker. The cold compression curve has here been
+        approximated by a 4th order Birch-Murnaghan EoS, as described in
         Matsui et al. (2012; https://doi.org/10.2138/am.2012.4136).
     """
 
     def __init__(self):
         def _pressure_Decker_NaCl(volume, temperature, params):
             # Isothermal pressure (GPa)
-            P0 = pressure_birch_murnaghan_fourth(params["V_0"] / volume, params)
+            P0 = pressure_fourth_order(params["V_0"] / volume, params)
 
             # Thermal pressure
             thermal_model = MGDBase()

burnman/classes/mineral.py

@@ -64,12 +64,13 @@ def set_method(self, equation_of_state):
         """
         Set the equation of state to be used for this mineral.
         Takes a string corresponding to any of the predefined
-        equations of state:  'bm2', 'bm3', 'mgd2', 'mgd3', 'slb2', 'slb3',
-        'mt', 'hp_tmt', or 'cork'.  Alternatively, you can pass a user defined
-        class which derives from the equation_of_state base class.
-        After calling set_method(), any existing derived properties
-        (e.g., elastic parameters or thermodynamic potentials) will be out
-        of date, so set_state() will need to be called again.
+        equations of state:  'bm3shear2', 'bm3', 'mgd2', 'mgd3',
+        'slb2', 'slb3', 'mt', 'hp_tmt', or 'cork'.
+        Alternatively, you can pass a user defined class which
+        derives from the equation_of_state base class. After
+        calling set_method(), any existing derived properties
+        (e.g., elastic parameters or thermodynamic potentials)
+        will be out of date, so set_state() will need to be called again.
         """
 
         if equation_of_state is None:

burnman/eos/__init__.py

@@ -14,8 +14,7 @@
 
 from .equation_of_state import EquationOfState
 from .murnaghan import Murnaghan
-from .birch_murnaghan import BM2, BM3
-from .birch_murnaghan_4th import BM4
+from .birch_murnaghan import BM3Shear2, BM3, BM4
 from .mie_grueneisen_debye import MGD2, MGD3
 from .slb import SLB2, SLB3, SLB3Conductive
 from .modified_tait import MT